Advances in understanding mental diseases, from a bio-psycho-social perspective, have widened therapeutical resources and, thus, promoted the use of multidisciplinary approaches as well as the creation of services to replace traditional psychiatric hospitals. The World Health Organization (WHO) has recommended that studies be performed on the satisfaction and overload of mental health service staff members as a means to systemizing evaluation processes and improving service quality. In the present study, staff members belonging to inpatient and outpatient mental hospitals in the city of Ribeirão Preto answered WHO's scales on mental health staff satisfaction (SATIS-BR) and impact on work (IMPACTO-BR), and Lipp's Stress Symptoms Inventory (ISSL) with the aim to investigate the levels of satisfaction, overload, and professional stress. Of the total 172 individuals who took part in this study, 136 were hired professionals, and 36 were psychiatry resident physicians. Data collection was performed in six psychiatric units, of which three were from the same university hospital (one day hospital, one psychiatric ward, and one short stay ward). The other three units were a center for psychosocial care and two psychiatric hospital units, one for female and the other for male patients. Results for the sample of hired professionals showed an average satisfaction score of 3.26 (range between 1 and 5), with higher scores for the factors "Service Quality" and "Relationships at Work", and lower scores for the factors "Work Conditions" and "Participation in the Service". Significant differences were observed between two units of the same hospital. For this same sample, the average overload score was 1.85 (range between 1 and 5), and the results from administrating the ISSL showed that stress occurred in 23% of the participants, who were most in the residence phase, with a prevalence of psychological symptoms. Overload scores and stress incidence were higher among resident physicians, compared to hired professionals. A negative correlation was observed between satisfaction and overload results. Continuous and regular service evaluations are needed in order to monitor satisfaction and burden of the staff, with the aim to improve services, while providing staff members with quality of life, and patients with better care.