Background: No published data on two-dimensional echocardiographic quantitation of left ventricular size and function in Indian mongrel dogs is reported till date. Methods: Reference intervals for linear and area measurements of left ventricle size and function was generated in fifty healthy mongrel dogs (25 males, 25 females; mean age=1.59±0.13 yr; mean body weight=16.66±0.73 kg) using two-dimensional echocardiography. Dogs deemed healthy after thorough clinico-physiological, hematological, radiographic, electrocardiographic and echocardiographic evaluation were included in study.Relationship between two-dimensional linear and area measurements of left ventricle and body weight and, between same measurements obtained from different tomographic planes was studied using linear regression analysis. Result: Linear left ventricular measurements, left ventricular internal and external area, mitral valve orifice area showed significant (P less than 0.001) positive correlation with body weight while fractional shortening and ejection fraction showed significant (P less than 0.001) weak negative correlation with body weight. Left ventricular internal length in diastole, interventricular septum thickness and left ventricular internal dimension in systole and left ventricular free wall thickness in diastole were significantly (P less than 0.01) higher in male dogs while mitral valve orifice area was significantly (P less than 0.01) higher in female dogs. All linear measurements of left ventricular size obtained from different tomographic planes displayed significant (P less than 0.001) correlation with each other.