One hundred and fifty-seven Chinese hamsters (Cricetulus griseus) from the Lovelace Foundation Inhalation Toxicology Research Institute colony had pulmonary granulomas, nodular hyperplasia of the liver, granulocytic bone marrow hyperplasias and myelogenous leukemia, nephrosclerosis and uterine adenocarcinomas. These Chinese hamsters had a median life span of 1 075 days. The long life span and information on naturally-occurring diseases suggest that this species might be more widely used for toxicological and biomedical research.