Dietary selenium intakes were determined over three seasons for 66 children aged 4-6 y in rural Malawi, and at one season for 67 children aged 6-10 y in rural Papua New Guinea. The selenium content of the foods consumed was assessed using instrumental neutron activation analysis. Median intakes of selenium for the Malawian children were 20 micrograms per day, 21 micrograms per day, and 15 micrograms per day at harvest, postharvest, and preharvest seasons, respectively. More than 43% of the Malawian intakes were below the U.S. Recommended Dietary Allowances for 4-6 y olds (20 micrograms per day). Median intake of Se for the Papua New Guinean children was 20 micrograms per day, with 87% of the intakes below the recommended level for 7-10 y olds (30 micrograms per day). Statistical comparisons of selenium intakes over three seasons for the 51 children present in all survey periods revealed that mean intakes were not significantly different in survey periods one and two, but decreased significantly in survey period three, when expressed per day (p less than 0.002), per MJ (p less than 0.003), or per kg (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)