Introduction.Though many clinicians who deal with spinal deformity do understand the meaning of idiopathic scoliosis, answer regarding its cause remains an enigma. Better understanding concerning its etiopathology should improve clinicians' ability to deal with this condition, to prevent its occurrence, to prevent the progression, to develop new treatment modality and to predict prognosis. Previous researches have shown that osteopontin had its role in development of adolescent idiopathic scoliosis and its severity progression. This study is intended to evaluate the association between osteopontin plasma levels with adolescent idiopathic scoliosis as part of the effort to understand the pathomechanism related to spinal asymmetrical growth, leading to development of adolescent idiopathic scoliosis. Materials and methods. Twenty five healthy adolescents and twenty two adolescents with idiopathic scolisis were enrolled in the study. They had their blood measured for osteopontin level. The measurements were conducted by quantitative enzyme immunoassay technique. Osteopontin level between groups was compared using student t-test. Correlation test was performed to evaluate the corrleation between osteopontin and severity of the scoliosis, skeletal maturity, and age.Results.The study showed that mean osteopontin level was increased in adolescent with idiopathic scoliosis compared to healthy adolescent. (175.4 ± 10.7 ng/ml versus 141.1 ± 83.8 ng/ml respectively). Severe scoliosis (above 45 degrees) had highest osteopontin plasma level (225.4 ± 109.3 ng/ml) while osteopontin level in adolescent with mild degree scoliosis and healthy control was 103.1 ± 45.0 ng/ml and 141.1 ± 83.8 ng/ml respectively. Osteopontin level had strong negative correlation to skeletal maturity and age (r = - 0.82, p = 0.00 and r = - 0.82, p = 0.00, respectively). Osteopontin level in scoliotic patients increased significantly in growth spurt period (257.4 ± 87.1 ng/ml, p < 0.05).Conclusions.Osteopontin plasma level was higher in adolescent idiopathic scoliosis patients compared to healthy control. The increased was significant during growth spurt period and in severe scoliosis. They indicate that adolescent idiopathic scoliosis patients experience higher degree of bone remodeling which lead to susceptible to spinal deformity in the presence of asymmetrical extraskeletal forces. Correlation between osteopontin plasma level and skeletal maturity and age might prospect this parameter to be used as a tool to determine the prognosis of scoliosis.