A 50-year-old man had severe ileus from strongyloidiasis. Pathologic examination of the appendix revealed the presence of an intact Strongyloides larva surrounded by an eosinophilic granuloma. This finding provides very strong evidence for Strongyloides as the causative agent of appendiceal eosinophilic granulomas previously only inferred to be due to Strongyloides in patients with evidence of strongyloidiasis.