The objective of this investigation was to determine the changes in proteins, lipids, and lipoproteins in liver and serum of rats acutely intoxicated with carbofuran (1.5 mg/kg sc). Under the influence of carbofuran acute intoxication, analysis of globulin fractions revealed remarkable changes: In liver, the levels of alpha‐2, alpha‐3, and gamma were significantly elevated while alpha‐1 was reduced; in serum, alpha‐1 and alpha‐3 fractions were elevated while alpha‐2, beta, and gamma remained unchanged. A transient increase in total protein and albumin was noted only in liver. Carbofuran produced significant increases in triglycerides and cholesterol in liver that were also seen in serum. In both the liver and serum the levels of low‐density‐lipoprotein cholesterol (LDL‐C) were reduced while the values of very‐low‐density‐lipoprotein cholesterol (VLDL‐C) were elevated. The concentration of high‐density‐lipoprotein cholesterol (HDL‐C) was drastically reduced in liver (23% of control) with a proportional rise in serum (176%). In liver, carbofuran caused marked depletion of adenosine triphosphate (ATP) and phosphocreatine (PCr) (38% and 22% of controls, respectively), resulting in increased cell membrane permeability, thereby allowing leakage of cell constituents. It was concluded that carbofuran, directly or indirectly, produced perturbations in lipoprotein metabolism.