The objective of this study was to assess the work capacity of the nurses of an emergency room, and relate it with individual and work characteristics. This cross-sectional study involved 68 workers of a university hospital in the state of Rio Grande do Sul, Brazil. The Brazilian version of a standardized questionnaire was used to obtain the Work Capacity Index. Results show that 42.9% of workers were classified as having a reduced work capacity. The most frequently diagnosed diseased over the last 12 months were: repeated respiratory tract infections, back injuries; varicose veins; mild emotional disorder; vision disorders; and upper back and neck conditions, causing frequent pain. In conclusion, the high of workers with reduced work capacity point at the importance of adopting intervention measures in the organizational structure to promote/restore capacity, from the perspective of improving health and work conditions