Ancylostoma duodenale in 74 patients and Ascaris lumbricoides in 41 were treated with a single 150 mg dose of levamisole, a single 300 mg dose of mebendazole or the standard three-day regimen of 200 mg mebendazole daily. Levamisole cured all of the 25 hookworm patients and all of the seven Ascaris carriers to whom it was given and is recommended as the drug of choice in Egypt.