The association between severe and persistent strongyloidiasis with human T cell lymphotropic virus type I (HTLV-1) infection is well documented in reports from HTLV-1 endemic regions like Japan and Jamaica. But there are no reports from non-endemic areas like India. We report a case of severe intestinal strongyloidiasis in a 45-year old Keralite man, living in Sikkim. Despite standard treatment with many courses of albendazole, his stool persistently showed Strongyloides stercoralis larvae. In the absence of other immunosuppressive conditions, human T cell lymphotropic virus type I infection was considered and determined positive. Subsequently, treatment with 2 courses of ivermectin achieved eradication of the infection. On follow-up, 3 years later, his stools again revealed Strongyloides stercoralis larvae.