The state takes the responsibility of protecting the life, health and working ability of inmates of penitentiary institutions. This study aimed to explore working conditions at a correctional facility located in Tatarstan. Among the most significant workplace hazards were high noise and vibration levels, poor lighting, exposure to increased concentrations of harmful substances in the air, physical distress, constrained posture, sensory stress, and monotonous work. Health evaluation of 5,009 incarcerated individuals exposed to poor working conditions revealed that they were more likely to develop work-related diseases than their counterparts who worked in the office. Among the former skin and subcutaneous tissue diseases, hearing impairment, respiratory conditions and cardiovascular disorders were 2.1, 1.7, 1.5 and 1.3 times more frequent, respectively. Our study revealed the lack of medical examinations on admission, as well as regular medical checkups, and the reluctance of the inmates to use personal protection at work. Based on the study results, adequate measures were taken to improve working conditions, raise awareness of hygiene problems among the inmates and initiate routine medical checkups. The number of incarcerated individuals working under bad conditions plunged from 68 % to 19 %. Also, up to 82 % of inmates started to use personal protection.