This article describes in general the issues related to the dysentery epidemic in 1920-1921. The current literature on the subject lacks publications presenting these issues fully. Based on historical sources from that period, including articles published in medical magazines, the incidence rate, the methods and results of the battle against that epidemic were depicted. The article represents an important contribution to a better insight in the struggle of Polish medical services with infectious diseases afflicting people in the first years following the end of World War I. It also sheds light on the development of Polish studies on infectious diseases in the Second Polish Republic, the scientists’ belief in the successful treatment of epidemic diseases and understanding of the need to educate people about the rules of hygiene and taking medicines.