We analysed data obtained from the Hawaii Tumor Registry, a population-based participant in the Surveillance, Epidemiology, and End Results (SEER) programme that monitors cancer incidence and mortality for the entire state. A total of 138 males and 116 females, under the age of 15, were diagnosed with leukaemia between 1960 and 1984, with average annual age-adjusted incidence rates of 49.6 and 44.8 per million, respectively. Time trend analysis by 5-year calendar periods revealed an increasing rate for leukaemia among females only, whereas other populations have shown a positive trend in both sexes. The incidence rates for all ethnic groups combined were similar to those for US whites. Japanese and Chinese males had a slightly higher rate for leukaemia than US whites, while Filipinos, Hawaiians and whites in Hawaii had relatively lower rates. Among females, incidence was higher among whites, Filipinos, Hawaiians and Chinese than among US whites, and lower among Japanese. Thus, there were notable sex differences in the ethnic distribution of this disease.