Objectives: The purpose of this study was to estimate differences in physical growth according to sleep during preschool period. Methods: Difference of height and BMI percentile according to quality and quantity of sleep obtained through survey from 377 preschool children was measured using statistical method. Results: There was no significant difference in height and BMI percentile according to bedtime, rising hour, sleeping hours and sleeping environment. Children who had woken up more from scare during sleep showed smaller height percentile. Conclusions: Children who woke up more from scare during sleep could have smaller height.