Vitamin D receptor gene polymorphism was determined in 66 and 60 Japanese patients with prostate cancer and non cancer controls, respectively. In contrast to previous reports showing an association between vitamin D receptor polymorphism of a TaqI restriction fragment length polymorphism at codon 352 (genotype tt) and prostate cancer in an American population, the frequency of genotype tt is less than one percent in the Japanese population. There was no difference between the patients and the controls in the vitamin D receptor TaqI genotype. In patients with metastatic prostate cancer, genotype TT had a tendency to shorter progression free survival compared to genotype Tt, but the number of patients was limited.