Atomic absorption spectrophotometry was used to detect lenticular nickel, chromium, manganese, iron and aluminum levels in 37 senile cataractous and 9 normal human lenses. The nuclear parts of the lenses were used for the study in both groups. It was found that the concentrations of nickel and iron were significantly higher, and those of chromium, manganese and aluminum were significantly lower in human cataractous lenses than those in normal human lenses. None of the elements showed a significant difference according to sex in both groups. As remarkable differences in chromium, manganese, iron, aluminum and nickel levels exist in cataractous lenses, all the five elements may play some roles in cataractogenesis.