The article presents an analysis of the formation and activity of the People’s Commissariat for Health Care of the Socialist Soviet Republic of Lithuania and Belarus at the beginning of 1919. The basic structure of the Commissariat was worked out on the basis of various sources. It was found that, due to the outbreak of the 1919–1921 Polish-Soviet war, the efficiency of the Commissariat during its time in Vilnius was limited. The relative stabilisation of the health-care management system was achieved after the Commissariat was evacuated to Minsk, and later to Bobruisk, away from the front line. It has been proven that at the beginning of the Polish-Soviet war, military and civil medical care was combined in a single system, and all medical professionals in the Lithuanian-Belarusian Soviet Republic were required to do military service. The worsening of the military situation for the Red Army in Lithuania and Belarus determined the split of the Health Care Commissariat into two separate divisions: the field division for medical care for Soviet troops near the front line, and the civil division for helping civilians.