The aim of this study was to investigate microplastic pollution in the vicinity of Horseshoe Island, located in Marquerite Bay, Antarctica, as a result of visits to the region for scientific research, tourist travel and natural transport events. Water samples from 3 lake stations (LAKE-1, LAKE-2 and LAKE-3) and snow samples from 3 different locations (SNOW-1, SNOW-2 and SNOW-3) were collected between 13 and 24 February 2023. The average particle concentrations in LAKE-1 and LAKE-2 samples were 17.58±4.12 particles/L and 22.42±4.12 particles/L, respectively.  In LAKE-3, 15.3 particles/L were found. While MPs were the most common fibre type in the lake samples, the most common size range was 1500-4999 µm (38.4±6.7% in all samples). The snow sample SNOW-1 had a concentration of 45.7 particles/L, while SNOW-2 had a concentration of 71.4 particles/L MPs. The sample from BASE Y (SNOW-4) had a concentration of 27 particles/L. The mean value of fibre type particles for all SNOW stations was 85.9±14.5%. When analysing the particle size distributions in the snow samples, 30.6±7.7% of the particles were 500-999 µm and 29.8±9.6% of the particles were 1500-4999 µm. The results indicate that the lakes and snow masses around Antarctic Horseshoe Island are contaminated with MPs. Keywords: Microplastics, polar region, microplastic pollution