Rationale: Nurses working in the intensive care unit (ICU) are constantly bombarded with stressful events and traumatic situations that may have deleterious effects on their health. The implications and the outcomes of exposure to these constant stressors by this workforce, on their mental health, are largely unknown. Objective: To determine and measure if critical care nurses are having more work-related mental disturbances compared to their counterparts who are working in less stressful environments such as wards. Materials and methods: We collected data from three large tertiary care hospitals in south India spanning over two states (n = 383 and 220 respectively) using various validated tools. Relevant data and results: In both cohorts of nurses, we determined the prevalence of symptoms of post-traumatic stress disorder (PTSD), depression, and anxiety using various validated tools such as PTSS-10 and hospital anxiety and depression scale (HADS). About 29% (CI 95%,18–37) of the ICU nurses were found to have symptoms PTSD, in comparison to 15% (95% CI,10–21) of the ward nurses (p = 0.04). The stress levels apart from the workplace reported by both groups were statistically similar. In the sub-domains of depression and anxiety, both groups faired equal probabilities. Conclusion: From this multicenter study, we have found that the staff nurses working in critical care areas of the hospital suffering from PTSD to a greater extent compared to their counterparts working in calmer ward conditions. This study will shower vital information to hospital administration and nursing leadership in improving the workplace mental health and satisfaction at jobs of ICU nurses working in tedious working conditions.