Itai-itai (ouch-ouch) disease is a syndrome accompanied by bone mineral disorders that may be related to oral cadmium exposure. Itai-itai predominantly affects postmenopausal women with a history of multiple childbirth. In a previous study we have examined the genotype distributions of PvuII and XbaI restriction fragment length polymorphisms of the estrogen receptor alpha (ER alpha) gene in patients with itai-itai disease and compared them with those of controls. However, no significant differences were shown between the genotype distributions of the patients and controls. In the present study, we determined the TA repeat polymorphisms of the patients and controls. The distributions of the patients were: HH 25.0%, HL 50.0%, and LL 25.0%; where HH includes two alleles with a high number of TA repeats (TA> or =16), HL includes one high number allele and one low number allele (TA< or =15), and LL includes two alleles with a low number of TA repeats. These patients' distributions were not significantly different from those of the controls. Although our sample number was limited, we concluded that a polymorphism variant of the ER alpha gene is not a predisposing factor for itai-itai disease.