During pandemic periods, mental health issues are highly prevalent, particularly among healthcare workers who are at a higher risk of developing psychiatric disorders. The aim of this study is to evaluate the mental health status of the intensive care unit (ICU) healthcare workers, who play a vital role in managing the COVID-19 pandemic, in terms of the quality of sleep, levels of depressive and anxiety symptoms, stress and to determine the factors that affect their mental health. The research was conducted in April 2020 and incorporated a total of 79 participants working in an university hospital ICUs in Turkey. Pittsburgh Sleep Quality Index (PSQI), Depression Anxiety Stress Scale 42 (DASS-42), Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI) were applied. Among the participants, 58 individuals comprising 73.4% of the cohort were working in the ICUs, managing patients infected with COVID-19. Those working in ICUs with COVID-19 patients had significantly higher DASS-S, BAI, and BDI scores. Doctors' BDI scores were significantly lower compared to both nurses and other healthcare workers. Participants exhibiting COVID-19 symptoms manifested significantly higher BAI scores in compared to those without such symptoms. Healthcare workers involved in ICUs with COVID-19 patients were more significantly affected psychologically, doctors had lower depressive symptoms as compared to other healthcare workers. In addition, individuals with COVID-19 symptoms demonstrated significantly higher levels of anxiety. The findings of our study emphasize the significance of providing psychological support to healthcare workers throughout pandemics.