Flail chest is a rare complication in pediatric patients with blunt chest trauma. There is no general consensus on which treatment is most appropriate for flail chest in pediatric patients, although it has been reported that surgical fixation is associated with beneficial outcomes for flail chest in adults. The present report described two pediatric cases of flail chest, which was rare in pediatric blunt trauma. In small children, functional residual capacity is smaller, and the thorax is pliable due to high thoracic compliance. Therefore, it is only advisable to select intubation and mechanical ventilation treatment. Likewise, in pediatric flail chest, the available evidence does not suggest that ventilator management protocols should be adopted routinely, and the treatment for pediatric flail chest was not established completely. There were not huge different between the described patients, including injury severity and ventilation setting. However, one had a relapse of flail chest after extubation and chest taping was required, while the other patient's condition was stable after decannulation. As described above, it is difficult to predict a recurrence of flail chest in pediatric patients even if treatment goes well. Therefore, T-piece trial should be considered prior to extubation.