Strongyloides stercoralis infection is a disease caused by an intestinal parasite. This helminth is highly prevalent in tropical and subtropical areas. The preferred treatment is ivermectin, and thiabendazole as a second option available in certain Peruvian institutions. The purpose of the study was to assess the efficacy and tolerability of thiabendazole (25 mg/kg/day) administered twice a day (after meals) for three days in individuals with S. stercoralis chronic infection. The study was conducted at Hospital de La Merced, Province of Chanchamayo, Peru (endemic area), during a 90 day period. The study included 32 individuals (22 female and 10 male, average age +/- SD = 9.31 +/- 8.11 years) with a diagnosed S. stercoralis infection. Follow up tests were eosinophil count, hematocrit, agar plate feces culture, and Baermann technique modified by Lumbreras. Healing rate was 90.6%. The average eosinophil count in healed patients significantly decreased (1168 to 665 eosinophils/cc, p=0.006) as compared to the treatment failure group, which showed a slight increase (618 to 897 eosinophils/cc, p=0.125). Hematocrit increased in both groups (2% and 3%, respectively). Adverse effects were headache, dizziness, and epigastralgia in 6.2% of individuals. It was concluded that the studied scheme showed a high effectiveness rate and was well tolerated. Therefore this scheme may be taken into account for control programs of this parasite in hyperendemic areas.