To evaluate the results of an ergonomic-educational course for nurses we assessed the number and percentage of harmful postures and of ergonomic and biomechanical errors made before and after the course. We also studied the perceived physical exertion. In all, 12 nurses who had participated in the course (trainees) and 12 who had not (controls) were recorded on video while performing standardized nursing tasks. The wards from which the two groups of nurses came were comparable, as were the patient populations. The nurses were also comparable in some personal characteristics. The tasks they performed included washing, lifting, and repositioning a patient as well as certain tasks other than patient handling. Video recordings were made once before (1-2 weeks) and twice after the course (after 3 months and after 15 months). The harmful postures, the errors made, and the ratings of perceived exertion were measured by means of the Ovako Working-posture Analysis System (OWAS), a checklist, and Borg scores, respectively. When the first and last measurements of all the above tasks taken as a whole were analyzed the trainees showed a significant improvement in the number and percentage of harmful postures and errors, whereas the controls did not. The same could be concluded for lifting alone. After the course the new work routine did not appear to have caused any extra perceived physical exertion. It can be concluded that the course was successful, although it should be carefully investigated as to whether nurses remain capable of working safely in daily practice. The work pressure that nurses experience during their normal duties could prevent them from working safely during everyday work.