Psychologic factors have been considered to play an important role in the etiology of chronic prostatitis. Earlier studies are often based on a psychoanalytical perspective and seldomly used quantitative approaches. In the present study quantitative tests are used to investigate personality variables which are suggested in the literature as underlying chronic prostatitis. A group of 50 chronic prostatitis patients was compared with a group of 50 patients seen for a vasectomy. Psychologic measures were taken by means of a personality inventory (NVM, Dutch short form of the MMPI), a symptom checklist (SLC-90), and a depression inventory (IDD). Results showed statistically significant differences between the groups, with the chronic prostatitis patients scoring consistently higher on the measures than vasectomy patients. However, these differences in scores were not of a great magnitude and minor compared with differences in scores from psychiatric patients. Discriminant analysis suggested somatization and depression to be the key variables to distinguish chronic prostatitis patients from vasectomy patients. Overall, it seemed unfounded to label chronic prostatitis patients "neurotic" or "psychopathologic," and it was impossible to conclude that there are personality variables that specifically identify the chronic prostatitis patients.