The sample consisted of 109 women in traditionally male professions and 112 women in traditionally female professions with a mean age of 51.8. Subject selection was based on whether women were under-represented or over-represented in particular fields as stated in the 1960 U.S. census. The Sixteen Personality Factor Questionnaire, the Adjective Check List, and the Biographical Questionnaire were employed. The findings indicate that women in traditionally male professions and women in traditionally female professions differed significantly on five of the sixteen personality factors, i.e., Factor A, Outgoing vs. Reserved, Factor B, Less Intelligent vs. More Intelligent, Factor H, Threat-sensitive vs. Venturesome, Factor M, Practical vs. Imaginative, and Factor N, Forthright vs. Shrews. Compared with women in general, both groups were emotionally stable, assertive, serious, conscientious, sensitive, adaptable, self-assured, experimental, self-sufficient, and self-controlled. Significant evidence of gradual development in masculine personality traits of women in traditionally male professions is provided by their own statements of being more independent and assertive. (Author)