Results: Number of infants with one or more diarrhea episodes was less by 17% (95% CI: 1% to 35%) in the zinc group but the numbers for ARI were similar in the two groups. The hospitalization rates due to all causes or diarrhea or ARI were similar in the two groups. Twelve in the zinc group and 9 in the placebo group died during 4 weeks to 6 months (p=0.36). We observed no significant difference for gain in weight and length at 3 months and 6 months between the groups. In a subgroup of infants the mean serum zinc concentration in the zinc group was 27% higher (p=0.004) than the placebo group.