The current research was aimed to investigate the relation between sleep quality (mental quality of sleep, sleep latent period, sleep duration, usefulness of sleep habits, sleep disruptors, hypnotics usage, and individuals' daily bad performance) and mental health and job burnout. 202 fire stations employees in Ahvaz were selected by simple random sampling method. Participants completed sleep quality, mental health, and job burnout questionnaires. The data was analyzed by simple correlation, enter and stepwise multivariate regression. The findings revealed that there is a significant relation between sleep quality and job burnout and mental health. Also, results showed that among subscales of sleep quality, mental quality of sleep was the best predictor of mental health, and daily performance interruption, the best predictor of job burnout. Considering the significant relationship between undesirable mental health with job burnout and low quality of sleep among employees, it is suggested that any intervention programs for preventing and reducing mental health problems, burnout and sleep quality among employees, should focus on reducing stressful work environment and sleep health training.