To review the outcomes of laser supraglottoplasty performed in children with symptomatic laryngomalacia and determine the factors influencing them. We retrospectively reviewed the medical records of patients who underwent laser supraglottoplasty for symptomatic laryngomalacia at the Lausanne University Hospital from November 2001 to November 2014. We examined the patient's demography, symptoms, comorbidities, type of laryngomalacia, synchronous airway lesions, and final outcomes. Seventy-nine patients were included in this study; median age at the time of surgery was 12.7 months. 55.7 % of the cases had comorbidities, 22.8 % of the patients were premature and synchronous airway lesions were present in 32.9 % of the cases. The different morphological types of laryngomalacia (I-III) were seen in 26.6, 62 and 11.4 % of the patients, respectively. Overall, operation specific success rate of laser supraglottoplasty was 86.1 %. Failures in 11 (13.9 %) of the 79 cases required 15 revision procedures. Success rates for patients with associated comorbidities, synchronous airway lesions, neurological disorders and prematurity were 81.8, 76.9, 69.2 and 66.7 %, respectively. Patients with type III laryngomalacia had a limited success rate (66.7 %) as compared to patients with morphological types I and II (90.5 and 87.8 %, respectively). Laser supraglottoplasty is an effective and safe treatment for symptomatic laryngomalacia. Patients with prematurity, type III LM, synchronous airway lesions and associated comorbidities are predisposed to surgical failure.