Oestrus ovis larvae, Linnaeus 1761 (Diptera: Oestridae) are obligatory parasites of the nasal cavity and sinuses of sheep and goats in many parts of the world. After inspection of a slaughtered goat in Kalat Naderi region in Mashhad (East of Iran) in 2012, 25 larvae were observed within the horns without any larvae being present in the sinuses. The larvae were identified morphologically as those of Oestrus ovis.  Oestrosis  is  a  widespread  myiasis  which  may  severely  impair  the  health  of  small ruminants. Oestrus ovis larvae are also responsible for causing human ophthalmomyiasis, and this infection is often misdiagnosed as acute conjunctivitis. Oestrus ovis is an economically important parasite of nasal cavities and the adjoining sinuses in sheep and goats worldwide. It causes losses in meat, wool and milk production. To the author’s knowledge, this is the first recorded case of horn infestation in goats by the larvae of Oestrus ovis in Iran without the sinuses being affected.