Osteocalcin is a specific and reliable marker which increases with rapid bone turnover and gives data about bone metabolism. The pubertal growth spurt is also known as a good example of rapid bone turnover. The aim of this study was to determine whether osteocalcin is a useful marker for the pubertal growth spurt period. In this study, osteocalcin levels in male adolescents were examined in relation to their sexual maturation stage and age. The osteocalcin levels and alkaline phosphatase levels were compared during the pubertal growth spurt. Serum osteocalcin and alkaline phosphatase levels were evaluated in 100 eligible healthy male children and adolescents (aged 10 to 17 years). Five groups (n: 20 each) of children and adolescents were formed according to their sexual maturation stages. Finally, the subjects were divided into three main groups in relation to the pubertal growth spurt and sexual maturation stages. Data were evaluated and compared among these three groups: First group = Stage 1 (prepuberty) + Stage 2 (early puberty) consisted of 40 (20 + 20) children and adolescents. Their mean osteocalcin value was 17.2 +/- 6.3 ng/ml and alkaline phosphatase 573.8 +/- 143.9 IU/L. Second group: Stage 3 + Stage 4 consisted of 40 (20 + 20) children and adolescents. These groups were known as the pubertal growth spurt groups. Their mean osteocalcin value was 29.4 +/- 10.6 ng/ml and alkaline phosphatase 728.4 +/- 233.9 IU/L. Third group: In this group, there were 20 children and adolescents who reached Stage 5 of sexual maturation and whose pubertal growth spurt was slowing. Their mean osteocalcin value was 15.3 +/- 5.8 ng/ml and alkaline phosphatase 435.8 +/- 184.8 IU/L. During the pubertal growth spurt, there is a relationship between bone remodelling and increasing osteocalcin and alkaline phosphatase levels. When sexual maturation reaches Stage 4 at 14 years old, osteocalcin and alkaline phosphatase levels make a peak, associated with the rapid growth in height. As sexual maturation reaches Stage 5, osteocalcin and alkaline phosphatase levels gradually decrease with growth maturation and their levels decline to the level of adults at the completion of this period. Our study showed that osteocalcin and alkaline phosphatase levels can be used as markers for evaluation of the growth spurt period.