ABSTRACT. Teratomas are histologically complex tumors arising from germ cells of two or three embryonic layers either in the gonads or occasionally from germ cells that mistakenly migrated to ectopic sites. A case of retroperitoneal teratoma in a regularly slaughtered 4-month-old, male domestic rabbit is reported. A pale reddish, 3 4 cm, fibrous mass was detected, loosely connected to the parietal wall in the retroperitoneal region cranial to the kidney. Histologically, the neoplasm contained tissues from ectodermal, endodermal and mesodermal germ layers: nerves and neurons simulating ganglia, cysts lined by squamous epithelium containing keratin and hair, skin adnexa; respiratory glandular epithelium, serous and salivary glands; collagenous connective tissue, muscle fibers, mature cartilage and bone, bone marrow, teeth and fat. To the authors' knowledge this is the first report of a retroperitoneal teratoma in the rabbit.