Belgica antarctica Jacobs (Diptera: Chironomidae) is the only endemic insect found in the Antarctic Peninsula region and has stimulated considerable research interest. Due to recent rapid changes in regional climate in Antarctica, there is growing interest in studying the responses of this species to environmental changes, in particular at the chromosomal level. Chromosomal inversions are known to play an important role in speciation and adaptation in many insect species, but their frequencies in natural populations are poorly understood. In the current study, we provide the first standard polytene chromosome map for B. antarctica , which will enable the precise location of chromosomal abnormalities in future studies. We further analysed chromosomal polymorphisms in fourth-instar larvae collected from two different locations on Galindez Island, Argentine Islands, western coast of the Antarctic Peninsula. We found four previously reported and two new inherited inversions, and we discuss their possible adaptive role in response to environmental stressors in the Antarctic Peninsula region. Our data provide a foundation for future studies exploring the potential role of B. antarctica chromosomal polymorphisms in adaptation to the changing environment.