BACKGROUND: Hymenolepis nana, also called dwarf tapeworm infection, is an intestinal helminth not previously reported in The Gambia and only very rarely reported in West Africa. CASE PRESENTATION: We report a case of H. nana infection in a 29-month-old child living in a rural community of the north bank of the Upper River Region (URR) in The Gambia. The child presented with mild iron deficiency anaemia and granulocytosis but was otherwise mostly asymptomatic despite the moderate-intensity of infection. CONCLUSIONS: We support treatment of H. nana infection even in largely asymptomatic children to prevent autoinfection and spread of this intestinal helminth in The Gambia and in other West African countries. ABBREVIATIONS: GCP: Good Clinical Practice; HAZ: Height-for-age z-score; IHAT-GUT: Acronym for the Iron Hydroxide Adipate Tartrate Supplementation Study; ICH: International Conference on Harmonisation; SD: Standard Deviation; URR: Upper River Region; WAZ: Weight-for-age z-score; WHO: World Health Organization; WHZ: Weight-for-height z-score.