Introduction: Mental health is affected by several variables, among which the most important ones could be considered job burnout, social support and psychological hardiness. This study aimed to investigate the relationship of job burnout, social support and psychological hardiness with mental health among nurses.

Methods: This was a descriptive–analytical research from the correlation type. The statistical population included all the nurses of a governmental hospital in Tehran, Iran in 2015. Totally, 400 nurses were selected through multistep cluster sampling method. All of them completed the questionnaires including job burnout by Maslach & Jackson (2008), perceived social support by Zimet et al. (1988), Kobasa’s psychological hardiness (1979) and Goldberg & Hillier’s mental health (1979). Data was analyzed using Pearson’s correlation and multivariate regression with stepwise model using SPSS-19.

Results: Job burnout (r = 0.37) showed a statistically significant positive relationship with mental health of nurses and perceived social support (r = -0.56), and psychological hardiness (r = -0.53) showed a statistical significantly negative relationship with mental health of nurses (P < 0.01). In a predictor model, job burnout, social support and psychological hardiness predicted 54.9% of variance of mental health of nurses (R2 = 0.549).

Conclusions: According to the findings of this research, it is suggested that counselors and therapists decrease the rate of job burnout and increase the rate of social support and psychological hardiness in order to increase the mental health of nurses.