Marine litter is attracting attention of scientists and environmentalists worldwide, as it is easily entering the marine environment through river runoff, sewage systems or winds. Accordingly, ports, industries, maritime and road traffic, tourism and agriculture are the main producers of litter. Synthetic plastic products are particularly hazardous to the environment, as they are fragmenting into numerous tiny microplastics under the influence of intense solar radiation and mechanical agitation. Microplastics can originate from larger plastic items (i.e. secondary microplastics) or are entering the marine environment as primary microplastics. A steadily growing number of publications and reports are documenting the continuous littering of the marine environment and the consequences of microplastics on marine biota. In this study, the occurrence, distribution and composition of microplastics is being investigated in sediments of Slovenian beaches. Sediment samples were collected in March 2017 and are currently being analysed for comparison with results from a previous study conducted in July 2012. Microplastics are recovered from sediments by density separation and filtration. The particles are analysed by infrared spectroscopy to identify the polymer type of the plastics. Microplastics are abundant in Slovenian beach sediments. Most of the items are of irregular shape, including fibres, films and fragments, indicating that the particles mostly constitute secondary microplastics. In the previous study, it has been proven that tourism is not the main producer of microplastics. Accordingly, major polluters of the Slovenian coast are yet to be identified. The applied approach will provide in-depth information on the plastic pollution on the coast of Slovenia. The data generated in this project will be of societal importance, as pollution tends to reduce the aesthetic value of the environment and can, thus, reduce revenues from Slovenian tourism.