Both male and female Foleyella furcata were found in the subcutaneous tissue and abdominal cavity of an adult male wild-caught Senegalese chameleon (Chamaeleo senegalensis) This nematode species is endemic to Madagascar but has never been recorded from the continent of Africa. Prior to the chameleon's death, a migrating worm was seen under the skin in the abdominal and thoracic region. Huge numbers of small, sheathed microfilariae were detected in the blood smears. The chameleon was treated with a single dose (0.2 mg/kg s.c.) of ivermectin. Serious adverse reactions (complete inertia) developed within 24 hr after injection and lasted for 7 days, indicating either ivermectin toxicity or a systemic reaction involving the release of endotoxins from the microfilariae dying in the bloodstream as a result of parasiticide therapy. Therefore, ivermectin treatment of chameleons infected with Foleyella should be avoided.