The KTP Laser was recently introduced in otolaryngology, and is increasingly used. This report describes treatment of 27 upper airway lesions in 24 children using KTP Laser over a two year and half period at the Children's Hospital of La Timone in Marseille. Comparison of results with CO2 Laser were made for the three most frequent pathologies of the series which were choanal atresia (n = 14), laryngotracheal stenosis (n = 6) and laryngeal paralysis (n = 3). The convenience of fiber delivery, concomitant telescopic control and low grade oedematous reaction are the main advantages over the CO2 Laser. As reported in the literature, we observed that healing was longer for KTP Laser than for CO2 Laser. Delay to healing may be an advantage in the management of choanal atresias and laryngeal stenosis.