The main aim of this study was to examine the measurement invariance of the Work Organization Assessment Questionnaire (WOAQ) across genders in a group of health care employees, using bifactor modeling. There is a very limited research that uses invariance testing of bifactor models, despite their usefulness. Establishing validity of the WOAQ in this way is important for demonstrating its relevance for both men and women.A bifactor modeling procedure was used here to examine the validity of the WOAQ with a sample of 946 paramedics employed in a large Australian organization in the health care sector.The results of this study show that the WOAQ has good psychometric properties across genders in health care settings. In addition, there were significant mean differences between men and women in their perceptions of "quality of relationships with colleagues," and "reward and recognition." There were no differences between men and women in the remaining factors: "quality of relationships with the management," "quality of relationships with colleagues," and "quality of the physical environment."The use of bifactor modeling to establish the cross-validity of the WOAQ across male and female paramedics adds to evidence for the measure's good psychometric properties. The findings confirm those of previous research that has used higher order confirmatory factor analysis. Moreover, mean differences between men and women were found to be significant in two of the five WOAQ subscales. These findings have practical implications for health care organizations, in terms of assessing work characteristics and developing activities to support the health and well-being of their employees.