The present study was designed to evaluate the possible adverse effects of acephate, an organophosphate insecticide, on hematological parameters in male albino rats. Acephate was administered orally to rats at either 25, 50, or 75 mg/kg bwt/day for 30 days. Data showed a significant decrease in total erythrocyte count, hemoglobin concentration, and hematocrit value; however, an increase in total leukocyte count was noted. The levels of blood sugar and blood urea were significantly elevated when administered by acephate. There were no significant changes in mean corpuscular hemoglobin, mean corpuscular volume, and mean corpuscular hemoglobin concentration for all doses. Thus, obtained results collectively revealed that acephate administration produced significant alterations in hematological parameters in dose-dependent manner.