A patient who experienced episodes of intestinal capillariasis caused by Capillaria philippinensis 16 times is presented. The patient was first seen in July 1967 with the parasitosis and was treated with thiabendazole. He experienced a relapse in October 1967. He was readmitted to the hospital again in 1969, twice in 1971, twice in 1972, twice in 1973, once each in 1975, 1976, three times in 1978 and twice in 1979. During this period he was treated with various dosages of thiabendazole, mebendazole and flubendazole. At the final admission he was treated with mebendazole, 600 mg per day for 49 days, 200 mg per day for 30 days and 100 mg daily for 6 months. The patient was cured and had no further relapses in 5 years. The recommended dosage of mebendazole is 200 per day for 20 days for new cases and 30 days for relapses. It is advised to over-treat the infection rather than under-treat because of the problem of relapses. Internal autoinfection occurs and it is believed that the drug acts selectively on the adults and not the larval forms of the parasite.