Sulfation is a key pathway in xenobiotic metabolism and chemical defense, and phenol sulfotransferase SULT1A1 plays a central role in this reaction. Genetic polymorphism of the SULT1A1 gene, SULT1A1, was reported to be associated with risks of several cancers; however, one study showed no significant relation between SULT1A1 genotype with prostate cancer risk. The present study was conducted to confirm the association of a G638A polymorphism, Arg213His, in SULT1A1 with familial prostate cancer risk in a Japanese population. A case-control study consisting of 126 cases and 119 controls was performed. In controls, GG, GA, and AA genotypes were observed in 85 (71.4%), 32 (26.9%), and 2 (1.7%), respectively; whereas, GG, GA, and AA genotypes were observed in 94 (74.6%), 32 (25.4%), and 0 cases, respectively. No significant differences were found in genotypic frequencies among cases and controls. Furthermore, stratification of cases according to clinical stages (localized or metastatic), pathological grades (Gleason score <7, or >7), age at diagnosis (<70 years or >70) and the number of affected relatives (2 or >2) did not show any significant differences among categories. These findings suggested that genetic polymorphism of SULT1A1 might not be involved in genetic susceptibility to prostate cancer.