The aims of this study were to investigate (1) perceived stress as felt by the nursing staff working in psychiatric inpatient care, (2) possible differences between nurses and nurse assistants, and (3) associations among individual characteristics, the ward atmosphere, the psychosocial work environment, and perceived stress. Ninety-three members of the nursing staff completed three instruments--one each measuring perceived stress, the ward atmosphere, and the psychosocial work environment. There were no differences among the staff groups concerning perceived stress. Multivariate analysis showed that the ward atmosphere factor "Involvement" and the psychosocial work environment factor "Role Clarity" were indicators of perceived stress. Improvements in these factors could help to prevent stress among the staff.