In studies on gender differences with respect to Holland's (1997) vocational interests, men often score higher on Realistic (and sometimes also on Investigative and Enterprising) interests, and women score higher on Social and Artistic interests. In research and practice, vocational interests are almost exclusively assessed by means of questionnaires. The aim of this study was to examine whether these results are also stable across assessment methods. Thus, a questionnaire and a nonverbal interest inventory were administered to a sample of N = 448 participants. Results were in the expected direction for both inventories, men scoring higher on Realistic interests and women scoring higher on Artistic and Social interests. However, the structure of interests varied between men and women. The structural assumptions of Holland's theory fit the data for men better than the data for women. Thus, mean-level gender differences should be interpreted conservatively.