The effect of delta sleep-inducing peptide (DSIP) intraperitoneal injection in the doses of 40, 120, 360, and 1080 mcg/kg b. w. on lipid peroxidation and functional hepatocyte state in Wistar male rats subjected to acute and chronic electrical foot-shock stress was investigated. It was observed that 120 mcg/kg peptide normalized the elevation of malondialdehyde (MDA) level in the liver homogenate caused by acute foot-shock stress and also significantly decreased catalase activity in all investigated doses. In serum the injection of DSIP up to 40 mcg/kg increased aminotransferase activity. Peptide in all doses provided the normalization of protein synthetic hepatocyte function, increased catalase and superoxide dismutase activity in chronic stress.