Strongyloides stercoralis infection is being increasingly diagnosed out of endemic areas. The aim of this study is to evaluate the usefulness of S. stercoralis serology for the management of probable strongyloidiasis in patients presenting with eosinophilia. Overall, 147 patients were included, 89 (60.5%) patients had a positive S. stercoralis serology. Strongyloides stercoralis larvae were detected only in 15 (10.2%) patients. Twenty-eight patients had human immunodeficiency virus infection. Eighty patients received ivermectin 200 mcg/Kg/day for 2 days, and follow-up 6 months after treatment could be performed in 32 patients: 26 (81.3%) patients reached the response to treatment criteria (negative serology 6 months after treatment or when by enzyme-linked immunosorbent assay the optical density ratio of post-treatment to pre-treatment decreased to 0.6), and 11 (34.4%) patients fulfilled the cure criteria (negative serology 6 months after treatment). Strongyloides stercoralis serology is a useful diagnostic tool both in the diagnosis of probable strongyloidiasis and follow-up after treatment.