Microplastics and other types of microlitter, such as paraffin, are found in environmental samples all over the world. Most of the studies have sampled surface waters, which have given us important insights on prevalence and transport. Due to the high turnover time associated with surface water samples and the often low number of particles obtained per sample, it is however not always possible to use surface water samples for a discussion on the composition on microlitter. Meanwhile, insight into the composition is crucial in order to investigate source patterns and to do risk analysis. The majority of the microlitter in the marine environment is expected to sink or get stuck on beaches. Here we therefore examine samples from beaches and sediment on the Swedish west coast. In the study we include three exposed beaches; Tjällsö, Skaftö and Ramsvik and three beaches close to urban and industrial areas in the outskirts of Gothenburg, Stenungssund and Uddevalla. We also investigate sediment samples outside of Stenungssund. At the beaches two types of samples were obtained. Accumulation samples; samples that were taken where the litter could visually be seen to be more concentrated and pooled samples; samples where smaller volumes across a larger area was taken and collected into one sample. There are currently no representative sampling methods for these types of rocky beach environments. The accumulation samples were therefore taken to increase the chance of having enough particles per sample to discuss around the sample composition and the pooled samples were considered a more representative form of sampling for this type of beaches. The samples were size fractionated and the analysis was done visually in a light microscope of the fractions 1-5 mm, 0.5-1 mm and 0.3-0.5 mm. Some particles were also analyzed using Fourier Transform Infrared spectroscopy to provide insights on the material types. Due to low particle numbers in some of the samples larger sample volumes would have been beneficial. In order to analyze larger volumes a suitable extraction protocol should however be adapted as the analysis would otherwise be too time consuming.Due to the complex source pattern that is associated with microplastics and other types of microlitter a more complete overview is achieved through combining environmental analysis and mass balance calculations. For queries regarding specific sources it is important to adapt the sampling and analytical method specifically since different sizes, particle densities and polymer types often require different methods. Extraction of micro litter from sediment samples is relatively well developed, for environmental monitoring but the analysis of smaller size fractions than 100μm need to be refined with respect to digestion of fine particulate natural interfering materials. The results indicate that beach samples can be suitable to analyze the composition of floating microlitter. Sediment on the other hand can provide complementary insights on sinking particles, especially those particles that have a higher material density but also materials that initially floats but later sinks due to degradation processes and biofilm formation. The beach samples revealed high concentrations of microlitter; in the pooled samples the concentrations varied between 4 000 and 100 000 particles >300 μm per kg d.w. and worst case samples on the beaches had up to 70 times higher concentrations. The most common type of microlitter in all samples was different types of plastic fragments. Among these transparent fragments were the most common. They are hard to trace to specific sources, although some insight into potential sources can be gained through investigating macrolitter compositions. Recurring results from Swedish beach inventories show that an important group of litter types is different types of plastic packaging. On the beaches another important category amongst the fragments was expanded cellular plastics, especially on the beaches close to urban and industrial areas where they composed a big part of the identified microplastics. A common type of expanded cellular plastics is polystyrene. Different strategies have been suggested to decrease the amount of expanded polystyrene in the environment, among those a reduced usage of single use materials made from expanded polystyrene. Since the main usage of expanded polystyrene is within the building and construction sector it would also be reasonable to look at the routines during construction work to ensure that no unnecessary spill into the environment occurs during transport and handling of the material. Amongst the microplastics that did not appear fragmented, plastic types related to the production of plastics made up an important part. Increasing concentrations were found in the smaller size fractions. It is likely harder to avoid leakage of these smaller fractions than of pellets. This therefore emphasizes the importance of the implementation of good routines, inspections and follow-up monitoring for activities related to production, transport and storage of the material. Another reoccurring type of litter was microspheres. Several microspheres were identified as polymethylmethacrylate whereas others gave similar spectral information as glass. In the literature it is also noted that some microspheres have been identified as polystyrene. Microspheres can therefore be expected to be made up of several different types of materials. Several kinds seem to leak to the environment which means that an overview of areas where they are being used can provide increased knowledge on different preventive steps that can be implemented to avoid spills during production, transport, storage and usage. Paraffin was also an important litter category that made up 21 % of the microlitter particles on the beaches. It can therefore be worth to consider potential risks that paraffin can constitute and to investigate the possibility to decrease leakage into the environment. The microlitter categories identified and quantified in the sediment study gave a complementary insight in important sources, such as tire wear particles, fibers, industrial spill of PVC, colored fragmented particles. However, also in sediments irregular semitransparent fragments, of light polymers PE and PP were of substantial significance in different sizes. A comparison with other concentrations reported for microplastics in sediment in the literature show that the concentrations found here, close to urban-industrial sources, are amongst the highest recorded concentrations for marine sediment. A comparison with the current knowledge on risk assessments of microplastics in sediment is therefore included in the discussion. In summary, the majority of the particles in both the beach and the sediment samples were fragments. That means that a program designed to decrease the amount of microplastics in the environment should include preventive steps against macrolitter, with focus on i) limiting certain use, ii) minimize outdoor handling, iii) barriers for leakage and dispersion, iv) cleanup actions, not only on beaches but also near sources or entry points to the environment.