Renal size varies with age, gender, body mass index, pregnancy and co-morbid conditions. Among different growth parameters, kidney's size is considered a critical criterion used not only in clinical evaluation of renal growth, rather used in abnormalities, and diseases. Conventionally, kidney size is measured roentgenologically. Nowadays, noninvasive ultrasonography has come into general use as a screening test for the kidneys. Since the renal size is affected by several factors, it is necessary to first establish the normal values. In our study, we aim to establish nomograms for renal size in the Lebanese young population from the age of 4 to 15 years old. Methods: In a prospective study carried out on a total of 358 Lebanese schools aged renal units in 179 children aged 4 to 15 years old, were examined. Results: Kidney dimensions were analyzed in terms of renal length, width, volume, and central echogenic region for both kidneys. During the maturation process from infancy through adolescence, growth of kidney shows a high correlation with gains in height, weight and BSA. Among the body parameters, our study showed that age was the one best correlated with the kidney dimensions followed by BMI, BSA, weight and height (P<0.0001). Conclusion: It is important for Lebanese children to have their own population specific nomograms of the kidneys in the studied age group.