Sixty-two children infected with Ascaris lumbricoides were treated with a single dose (5 mg per pound) of pyrantel pamoate. Fifty-three (85.5%) were cured as judged by a negative, direct fecal smear and ZnSO4 concentrate one week after treatment. Egg counts were much reduced in the remaining positive cases. A 2-day regimen (5 mg per lb daily) cured 37 of 38 (97.4%) Ascaris-infected children. Forty-three patients with hookworm infections were given 5 mg per pound of pyrantel on 3 consecutive days. Cure was achieved in 36 (83.7%) patients. The drug produced only mild side-effects. The chief complaint was low-grade abdominal cramp during the time when the ascarids were being expelled. There were no abnormal changes in the urinalysis, SGOT, or the serum bilirubin levels after single- or triple-dose regimens.