Objective: Joint cartilage and enthesis thicknesses could be detected by high-resolution ultrasonography. Normal reference ranges for age and sex have been reported in studies from various countries. Ultrasonographic evaluation of lower extremity enthesis and knee joint cartilage (KJC) thicknesses in healthy Turkish children was aimed. Material and Methods: This pilot study was designed as multicenter cross-sectional; KJC and 3 enthesis attachment area (proximal patellar ligament [PPL], distal patellar ligament [DPL], and Achilles tendon [AT]) measurements were made by ultrasound in 209 (F: 98, M: 110) healthy children aged 5-15 years from five centers. According to the age of the children included in the study, they were grouped as 5-10 years old and 10-15 years old. Ultrasound measurements were made by seven researchers trained in musculoskeletal system ultrasound using a 7.5-10 Mhz linear probe. Gray-scale images were acquired according to the standard protocol reported in the EULAR guideline. Results: A total of 342 entheses and 321 cartilage measurements were made from 208 healthy children included in the study. In the 5-10 age group, PPL, DPL, and AT thicknesses were found to be statistically significantly lower (p=0.00). A positive correlation was found between age and PPL, DPL, and AT (r=0.25, 0.47, and 0.30). It was observed that DPL and AT measurements in the 10-15 age group differed between genders, while PPL was not statistically different in both genders. No gender difference was detected in the enthesis areas in the younger age group. Thickness was found to be significantly higher in the 5-10 age group (p=0.00). There was a negative correlation between age and knee cartilage thickness (r=−0.24, p=0.00). KJC was found to be thicker in boys than girls in both age groups (p=0.00). Conclusion: This is the first multicenter study to evaluate enthesis and cartilage thickness in healthy Turkish children. These data will guide the ultrasound studies to be performed in various patient groups, especially in chronic rheumatic diseases.