Lymphoma with large granular lymphocyte (LGL) morphology in a heifer is described. The most noticeable macroscopic finding was neoplastic involvement of the skin, mucosae of the alimentary tract, urinary bladder, and uterus. Histologically, lymphoma cells with large numbers of fine eosinophilic granules predominated in the neoplastic tissue, and the granules were positive for perforin. Surface CD3, CD5 or WC1 was expressed by some neoplastic cells. In addition to the epitheliotropism that is a feature of ordinary γδ T-cell lymphoma, the neoplastic cells showed angiodestruction and erythrophagocytosis. These phenomena were thought to result from marked activation of neoplastic γδ T-cells. The present lymphoma was distinct from the previously reported bovine NK-like T-cell lymphoma in its tissue distribution, cytomorphology, cytochemistry, and immunophenotype. Since this lymphoma was regarded as a cytologic variant of γδ T-cell lymphoma, the term hypergranular γδ T-cell lymphoma seemed to be more appropriate than γδ T-cell LGL lymphoma.