This study was aimed at investigating the toxic effects of subchronic and chronic exposure to propetamphos (PRO) and cypermethrin (CYP) combination in mice. Seventy male Swiss albino mice were used for this study. Group 1 was maintained for control and given insecticide-free feed for 60 days. Group 2 was administered with 5.0 mg/kg/bw/day of PRO (LD50/20); Group 3 with 10.0 mg/kg/BW/day of CYP (LD50/20), Group 4 with PRO and CYP combination at the same doses in feed for 60 days. Blood samples, liver and kidney were taken on days 45 and 60 from 10 animals. Serum samples were analysed for biochemical parameters, and liver and kidney tissues were examined histopathologically. When compared to the control group with insecticide-treated groups, it was determined that cholesterol, triglyceride, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT) levels increased and albumin levels decreased (P<0.05), bilirubin levels increased (P<0.05) in Group 4. It was seen that triglyceride and bilirubine levels and ALP and GGT activities were more high (P<0.05) in Group 4 than other groups; also ALT activity and bilirubine level were high (P<0.05) in Group 4 at 60 day. In all treatment groups, necrosis of hepatocytes, cytoplasmic vacuolation, bile duct hyperplasia and mononuclear cellular infiltration were presented in liver. In Group 4 at 60 day, tigroid basophilic cytoplasm and hepatocellular hypertrophy of liver; necrosis of the tubular epithelial cells, cytoplasmic vacuolation, cellular infiltration and glomerular atrophy of kidney were seen. As a result, it was concluded that the exposure of mice to PRO and CYP for periods of 45 and 60 days cause to adverse effects on both liver and kidney functions and protein and lipid metabolism. These effects were observed to be more severe in the case of PRO-CYP exposure for 60 days.