Occupational stress is currently studied by the Job Demand/Control model of Karasek, and the Effort/Reward Imbalance model of Siegrist. In this study we have translated into Italian and validated the short form of the Job Content Questionnaire (JCQ) and of the Effort Reward Imbalance Questionnaire (ERI). The questionnaires were applied to 531 health care workers during periodical medical examinations. Estimations of internal consistency, based on the correlation among the variables comprising the set (Cronbach's alpha), in each case were satisfactory (alpha ranging from 0.76 to 0.89), with the exception of the control" scale of JCQ (alpha = 0.57). Exploratory factor analysis showed that "control" scale of JCQ, and "reward" scale of ERI could be divided into two and, respectively, three sub-scales. The Karasek's and Siegrist's models made distinct contributions to explaining perceived work stress. Both JCQ and ERI questionnaire may be useful in occupational health.