In adults, cerebral oxy-([O2Hb]) and deoxyhemoglobin concentrations ([HHb]) change characteristically at transitions of sleep stages. The aims were to assess these changes in adolescents and additionally to measure tissue oxygen saturation (StO2) by near infrared spectroscopy (NIRS). Previously it was reported that in adults [O2Hb] increased and [HHb] decreased at the transition from non-rapid eye movement sleep (NREMS) to REMS and wakefulness. Transitions to NREMS from REMS/wakefulness led to a decrease in [O2Hb] and an increase in [HHb]. We measured [O2Hb], [HHb] and tissue oxygenation (StO2) with NIRS approximately above the left prefrontal cortex in 12 healthy adolescent males (aged 10-16 years). We found comparable signs and magnitudes of changes in [O2Hb] and [HHb] as observed in adults. StO2 increased at the transitions from NREMS to REMS and decreased from REMS to NREMS and at sleep onset (all p < 0.01, linear mixed effects model). Changes in oxygen metabolism during sleep transitions are similar in adolescents and adults. In addition, we show for the first time temporal changes of StO2 at sleep transitions.