Pioglitazone, a member of the thiazolidinediones, is a potent, highly selective agonist for peroxisome proliferator-activated receptor gamma and is an excellent insulin sensitizer used in treating type 2 diabetes mellitus. The present study investigated the effect of pioglitazone on glucose, total cholesterol, triglyceride, low-density lipoprotein (LDL) cholesterol and high density lipoprotein (HDL) cholesterol, total proteins, albumin (ALB), alanine transaminase (ALT), and aspartate transaminase (AST) levels in 20 healthy Bengali male volunteers in a randomized, placebo-controlled study. Blood samples were collected before and 0.5-24.0 hours after a single oral dose of a 30 mg pioglitazone tablet. Plasma pioglitazone level was determined using a validated method of reverse-phase binary high-performance liquid chromatography. Blood lipid profile and levels of glucose, ALT, and AST were estimated using enzyme assay kits, plasma protein level was estimated by the biuret method, and plasma ALB level was determined colorimetrically. No significant change in blood glucose, total proteins, total cholesterol, triglyceride, HDL, and LDL levels was observed over the 24-hour assessment period, indicating no plasma biochemical alterations. There were no significant differences between baseline and 24-hour values of ALB, ALT, and AST levels, indicating a lack of liver toxicity. Our results indicate that a single dose of 30 mg of pioglitazone has no hypoglycemic or hypolipidemic effect or liver toxicity within 24 hours of treatment among healthy Bengali males.