A survey was carried out in 36 fluoride endemic villages of Mehsana District of North Gujarat. Urine and blood samples of fluoride-afflicted human population and their drinking water were analysed for fluoride content and compared with samples from different parts of Ahmedabad city (control). The fluoride content in water samples of Ahmedabad city was within the permissible limits, but was high in endemic villages. The urine and serum of individuals from these villages also showed a higher concentration of fluoride than in the control population. The enhanced Na+ and K+ levels in the urine of the fluorotic populations indicates a probable electrolyte imbalance and altered kidney functions. Similarly, higher activities of serum transaminases (SGOT and SGPT) might be due to altered liver function, since both of these enzymes are known markers (of liver function). Normal steroidogenesis in fluorotic subjects was evident by the unaffected serum testosterone levels. Serum cholesterol was also in the normal range which indicates that fluorotic subjects were not suffering from hypercholesterolemia. Serum sialic acid, a known marker for detection of fluorosis, was reduced in cases from endemic villages. This might be due to escalated concentration of glycosaminoglycans, which hinder hormone-receptor interaction. Thus, the above data reveal altered liver and kidney function in fluorosis-afflicted individuals with high urine and serum fluoride but low sialic acid levels compared to normal controls.