BACKGROUND Occupational stress results from the interaction of multiple risk factors, such as the physical environment, biological function disturbances, work content and organization and diverse psychosocial components. OBJECTIVE To study the frequency of symptoms and the main sources of job stress, perceived by professional and non professional health care workers and to compare gender differences. METHODS A group of specially designed, self-administered, questionnaires adapted by the main author and independently validated, were applied. The results of two symptoms, one work satisfaction, and one job stress scales are reported. RESULTS One hundred sixteen women and 89 men were studied, 143 are professionals and 62 non professionals (clerical and nurse auxiliaries). Forty percent had symptoms of job stress and 82 subjects were defined as "probable cases", according to the ratings on the symptom scales. There were significant differences in the frequency of symptoms between professionals and non professionals (34.3 and 69.2% respectively). The main differences in symptoms, sources of job stress and dissatisfaction were more closely associated to the occupational level than to gender. CONCLUSIONS A high frequency of job stress symptoms was observed in this sample of health care workers and the risk of occupational stress varies more with the occupational level than with gender.