The objective of the study was to evaluate the effect of passive transfer status, determined by measuring serum immunoglobulin (Ig) concentration 24 hours after parturition, on growth performance in buffalo calves allowed to nurse the dam during the first month of life. Serum Ig concentration 24 hours after birth ranged from 28.1 to 35.9 mg/ml, birth weight ranged from 29 to 41 kg, body weight 30 days after birth ranged from 48.5 to 62.9 kg. The Average Daily Gain (ADG) from birth to day 30 ranged from 448 to 1,089 g/d. Significant linear associations were detected between serum Ig concentration 24 hours after birth and day-30 weight (p< 0.05; $R^2$ = 0.31) and between serum Ig concentration 24 hours after birth and ADG from birth to day 30 (p<0.001; $R^2$ = 0.72). Results indicated that passive transfer status was a significant source of variation in growth performance when buffalo calves nursed the dam. Maximizing passive transfer of immunity by allowing calves to nurse the dam can increase growth performance during the first month of life.