Background: There are limited studies regarding the incidence of degenerative changes in asymptomatic adolescents. This study investigated the incidence of these changes in MRI and demographic factors affecting the presence of these changes.Methods: In a cross-sectional study, lumbar intervertebral disks of 84 asymptomatic adolescents aged between 12-18 years were evaluated using MRI in a educational training center in Tehran, Iran. The presence of degenerative changes in different levels was evaluated and demographic characteristics were compared between those with and without degenerative changes. The effects of these changes on mental and physical health were investigated using SF-36.Results: In total, 25.7% of disks were degenerated. The incidence of these changes was different in different levels. The incidence of degenerative changes was highest in L4-L5 level (45.2%) followed by L5-S1 (36.9%) and lowest in L1-L2 (5.9%). The mean of age of subjects with degenerative changes was significantly higher (p < /em>=.005). Gender and body mass index (BMI) had no effect on incidence of degenerative changes. The presence of these changes decreased the physical, mental and total score of SF-36 only at L3-L4 level, but not in other levels.Conclusions: The degenerative changes in lumbar disks occur at earlier ages and have no symptoms. These changes do not affect the quality of life. BMI has no role in development of degenerative changes in adolescents but increased age is associated with increased risk of disk degeneration.