A liver of a 50-day old American bronze turkey (Meleagris gallopavo domesticus) was sent to our laboratory for examination from a commercial firm in Ankara. In the macroscopic examination, it was seen that there were yellow-coloured necrotic foci on the liver. Giemsa stained smears were prepared from these foci and examined microscopically. As a result of the examination, several trophozoites ranging from 10 to 19 µm were detected. Histomonosis was diagnosed by considering the information obtained from the owner, necrotic foci detected in the liver and trophozoites seen in the microscopic examination.