Abstract: The effect of a combination of albendazole and mebendazol was evaluated by stool exa mination in 7 patients with Ascaris lumbricoides eggs,7 patients with Trichuris trichiura eggs and 9 patients with hookworm eggs.Albendazole and mebendazole were given at 300 mg and 375 mg,respectively.Both drugs were divided into 3 parts, one part b.id., and given in 1.5 days.The fecal eggs turned negative in all the patients with Ascaris infection in 3 days,while the fecal eggs were negative in all patients with Trichuris or hookworm infection in 5 days.The development rates of the eggs were remarkably lower post treatment than pre treatment.It was found that the ovicidal rates in human ascariasis,trichuriasis and ancylostomiasis were 98.8% ,100% and 100%,respectively on the second day following the initiation of treatment.The results showed that the worm repelling and ovicidal effect of the combined chemotherapy was more evident.