To determine if NMR techniques might be used to detect hepatic steatosis secondary to protein malnutrition, the T1 and T2 relaxation times of liver tissue from rats subjected to long-term protein malnutrition were measured in vitro. The liver tissue from rats fed a protein-deficient rat chow (PD) for 37 days (N = 9) was characterized by increased proportion of fat (P < 0.001) but decreased water and nitrogen contents (P < 0.001) relative to controls (N = 9). Mean T1 times were significantly shorter and T2 times significantly longer in liver tissue from protein-depleted animals (P < 0.001). There was no overlap of T2 times between the protein-depleted and control animals. The consistent changes in T2 that occur with fatty infiltration of the liver should be detectable by current NMR imagers. © 1985.