Mice injected i.p. with 1.4 mg Corynebacterium parvum (C. parvum) displayed minor transient impairment of hepatic function, as evidenced within 5-8 days by significant elevations in serum aspartate aminotransferase and reductions in total protein, albumin and alkaline phosphatase. Inoculation of animals with the Landschütz ascites carcinoma (LAC) caused similar but more marked and prolonged liver injury with serological evidence of nephrotoxicity at advanced stages of tumour growth. Injection of C. parvum 24 h before tumour had no further influence on these serological changes observed in animals given tumour alone. No evidence was obtained to support histological findings that the LAC inhibits the granulomatous inflammatory response to C. parvum in mouse liver.