Studies in innovative curricula have shown that a written test of skills is potentially able to predict OSCE scores. In this study we verified the potential of a written test of skills as an alternative to an OSCE in two traditional medical schools. A 12 station OSCE was scored using detailed checklists and global rating scales. The written test of skills consisted of 132 true-false questions. Students were assessed immediately before graduation in 1997. The size of the reported correlations confirms that the written test of skills can be used to predict performance-based test scores in traditional medical schools to some extent. For research purposes, particularly for outcome research to compare curricula of medical schools, a written test of skills is a viable alternative to performance-based testing. A written test of skills is unable to replace the OSCE for assessment of individual students.