A study was made of the effects of fluoride (F) on the antioxidant defense systems of postmenopausal women residing in a fluorotic and a nonfluorotic village in Chitoor district, Andhra Pradesh, India. Twenty-five postmenopausal women (approximately 10 years postmenopause, mean age 57 years) residing in endemic fluorotic Adharam and nonfluorotic Rajanagaram (water F >2.0 ppm and <0.35 ppm, respectively) were studied for their dietary calcium (Ca), urinary F, serum levels of F, Ca, phosphorus, intact parathormone (PTH), 25-hydroxy vitamin D, and malondialdehyde (MDA), as well as the activities of serum alkaline phosphatase (SAP), glutathione S-transferase (GST), and catalase (CAT). Dietary Ca was far below the recommended daily allowance. Serum 25-hydroxy vitamin D and PTH levels were comparable in the two villages. Antioxidant and lipid peroxidation levels were significantly lower in the postmenopausal women residing in the Adharam fluorotic village. The postmenopausal women in the nonfluorotic Rajanagaram village showed a strong positive correlation between CAT and PTH (r = 0.54; p<0.01) and a negative correlation between CAT and SAP (r = –0.52; p<0.008). In the fluorotic village, MDA showed an inverse negative correlation with serum F (r = –0.6; p<0.001) and a positive correlation with dietary Ca (r = 0.43; p<0.03). GST showed a negative correlation with PTH (r = –0.42; p<0.04). For the women of comparable age, duration of menopause, and vitamin D status, those residing in the fluorotic village showed a weaker antioxidant defense system and lower lipid peroxidation than the women residing in the nonfluorotic village. The weakened antioxidant system among women in the fluorotic village is correlated with their high serum F levels and appears to have a detrimental effect on their bone mineral metabolism and mineralization.