Ten adult patients with proven fasciolosis were enrolled in the study. Serum samples were obtained before and one month after successful treatment using a single oral dose of triclabendazole. It was observed that, serum triglycerides (TG) and very low density lipoproteins (VLDL-C) increased, while serum total cholesterol, high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) exhibited a significant decrease. These changes were due to the degenerative necrotic damage of the hepatocytes. One month after treatment, the serum level of total cholesterol, HDL-C and LDL-C gained normal values, indicating recovery of the liver and restoration of its functions in cholesterol synthesis and esterification, while TG and VLDL-C were still significantly higher than control values. This might indicate that hepatic triglyceride lipase requires a longer period to return to a normal level.