This study was carried out to evaluate the effects of organophosphate (OP) insecticide chlorpyrifos on cardiac morphology and function in rabbits using echocardiography. Twenty New Zealand male rabbits were divided equally into four groups. Rabbits were exposed to chlorpyrifos in drinking water at concentrations of 0, 125, 250 or 375 ppm for 90 days. The comparison among the groups indicated that 375 ppm chlorpyrifos resulted in significant decrease (p<0.05) in heart rate (HR), cardiac output (CO), left ventricular fractional shortening (FS), left ventricular ejection fraction (EF), percentage thickening of left ventricle posterior wall (PWT), and significant increase (p<0.05) in left atrial diameter (LA), left ventricular internal diameter in end diastole (LVIDD), left ventricular end diastolic (EDV) and end systolic volumes (ESV) compared to those of the control group. These results showed that chlorpyrifos induces cardiac dysfunction in rabbits.