Microplastic pollution has received increased attention recently due to potential threat to marine biota and human health. This study reports microplastic (MP) content in brown shrimp (Metapenaeus monocerous) and tiger shrimp (Penaeus monodon) inhabiting in the shallow and offshore waters of the Northern Bay of Bengal, Bangladesh. Gastrointestinal tract (GT) of shrimps (n = 150) were examined for MPs following alkali digestion, microscopic observation and chemical analysis by micro-Fourier Transformed Infrared Spectroscope (μFTIR). A total of 33 and 39 MP items were found in P. monodon and M. monocerous, averaging 3.40 ± 1.23 and 3.87 ± 1.05 items/g GT, respectively. Among various shapes, types and colours of MP, filament (57–58%), fiber (32–57%) and black (48–51%) were dominant amongst the various particles identified. Tiger shrimp had high numbers (23 items) of larger size fractions of MPs (1–5 mm) but brown shrimp had high numbers (15 items) of smaller MPs (250–500 μm), and μ-FTIR data confirmed 13 particles of polyamide-6 and 6 particles of rayon polymers. These results provide a baseline of MP contamination in seafood from Bangladesh that should be useful for future monitoring efforts. Display omitted •MP items in two shrimps were ranged 33–39 with a mean abundance 3.40–3.87 items/g GT.•MP particles were dominated by black fibers and filament.•MPs were composed of polyamide-6 and rayon polymers.•MPs may transfer to humans as shrimps are often eaten without removing the intestines.