A rare case of myeloid leucosis was diagnosed based on characteristic gross and histopathological lesions in a backyard chicken which was presented for post-mortem examination to the Department of Pathology, College of Veterinary Science, Korutla. Grossly, multiple, soft, friable, cream coloured nodules of varied size were noticed on inner surface of ribs, sternum, at costochondral junction, pelvis, vertebral column, keel bone, on the serosal surface of peritoneum, liver, lungs, air sacs, heart and kidneys. Cut section of the nodule was grey to white colored, soft and granular in consistency. Liver and spleen were enlarged, fragile and yellowish grey colored. Kidneys were markedly swollen and had light grey to white colored tumour masses on its surface. Histopathological examination of the affected tissues revealed marked intravascular and extravascular proliferation of solid masses of uniform mature myelocytes. The tumor cells had a large, hyperchromatic, vesicular, eccentrically placed nucleus and few eosinophilic cytoplasmic granules.