Background: Small for gestational age (SGA) infants are at risk for low final height or weight. This study aimed to determine the frequency of catch-up growth in SGA infants. Materials and Methods: This cross-sectional study was carried out to study the infant’s growth process born in Kashan during 2009-2010. The infants with birth weight or height below 3 percentile were considered as SGA. A comprehensive history from mother’s diseases during pregnancy, birth grade, and parent’s education were provided. The children who achieved their height or weight for length above the 3th percentile (age<2 year) or BMI above the 5thpercentile (age≥2 year) were considered as those who caught up growth. Results: One-hundred fifty one children were included in the study (mean birth weight =1931 gram, birth height=43.63 cm and gestational age=36.28 week). Eighty-five children (56.3) were female. At the time of study, 116 (76.8) children were above the 3rd percentile for height; 124 (82.1) children were above the 3th percentile of weight for length or above the 5thpercentile for BMI; 20 (13.2) children were below the third percentile for height and weight. The mean corrected age at the time of catch-up was 1.08 and 1.41 year for weight and height, respectively. Catch-up growth was associated with higher weight, height and head circumference at birth. Conclusions: The failure to weight or height catch-up growth in children born with SGA is common. Therefore, the early recognition and referral of such children is a necessity
