Prostatic carcinoma is the leading cancer among American men, yet few risk factors have been established. Although increased androgen levels have long been associated with both prostatic carcinoma and baldness, to date no studies have shown an association between hair patterning and prostate cancer risk. A lack of standardized instruments to assess baldness or the assessment of hair patterning during uninformative periods of time may have precluded the ability of previous studies to detect an association. We hypothesized that baldness, specifically vertex baldness, should be assessed using standardized instruments and during early adulthood if an association with prostate cancer risk is to be found. To test this hypothesis, we included identical items related to hair patterning in surveys that were administered in two distinct prostate cancer case-control studies (Duke-based study, n = 149; 78 cases; 71 controls and community-based study, n = 130; 56 cases; 74 controls). In each, participants were provided with an illustration of the Hamilton Scale of Baldness and asked to select the diagrams that best represented their hair patterning at age 30 and again at age 40. From these data, the following five categories were created and compared: not bald (referent group); vertex bald early onset (by age 30); vertex bald later onset (by age 40); frontal bald early onset (by age 30); frontal bald later onset (by age 40); and frontal (at age 30) to vertex bald (at age 40). Separate analyses of the two studies are consistent and suggest an association between vertex baldness and prostate cancer [vertex bald early onset odds ratios, 2.44 [confidence interval (CI), 0.57-10.46)] and 2.11 (CI, 0.66-6.73), respectively; vertex bald later onset odds ratios, 2.10 (CI, 0.63-7.00) and 1.37 (CI, 0.47-4.06), respectively]. Although statistical significance was not achieved in either one of these studies, the concordance between the data suggests a need for future studies to determine whether early onset vertex baldness serves as a novel biomarker for prostate cancer and whether androgen production, metabolism, or receptor status differs among these men when compared to those who exhibit other types of hair patterning.