The effort-reward imbalance (ERI) model has been used to assess the health impact of job stress. We aimed at describing the cross-cultural adaptation of the ERI questionnaire into Portuguese and some psychometric properties, in particular internal consistency, test-retest reliability, and factorial structure. We developed a Brazilian version of the ERI using a back-translation method and tested its reliability. The test-retest reliability study was conducted with 111 health workers and University staff. The current analyses are based on 89 participants, after exclusion of those with missing data. Reproducibility (interclass correlation coefficients) for the "effort", "'reward", and "'overcommitment"' dimensions of the scale was estimated at 0.76, 0.86, and 0.78, respectively. Internal consistency (Cronbach's alpha) estimates for these same dimensions were 0.68, 0.78, and 0.78, respectively. The exploratory factorial structure was fairly consistent with the model's theoretical components. We conclude that the results of this study represent the first evidence in favor of the application of the Brazilian Portuguese version of the ERI scale in health research in populations with similar socioeconomic characteristics.