Objective. To determine the incidence of preoperative and postoperative aspiration in infants who undergo supraglottoplasty. To determine the effect of cold steel and CO(2) laser supraglottoplasty on aspiration in infants with severe laryngomalacia. Design. Retrospective study. Setting. Tertiary pediatric hospital. Patients. Thirty-nine patients who underwent CO(2) laser-assisted supraglottoplasty (CLS) or cold steel supraglottoplasty (CSS) for severe laryngomalacia. Main Outcome Measures. Aspiration and upper-airway obstruction. Results. Thirty-nine patients met inclusion criteria (18 males, 21 females). Eighteen patients underwent CSS and 21 patients underwent CLS. 10/39 (25.6%) of the patients had preoperative aspiration, and 2/10 (20%) resolved after supraglottoplasty. New onset aspiration was found in 4/13 (30.8%) in the CSS group and 9/16 (56.3%) in the CLS group. Conclusions. There is no significant difference in the rate of postoperative new-onset aspiration or relief of upper-airway obstruction in the CLS or CSS, is temporary and can be managed with thickened diet or temporary tube feedings. The rate of persistent postoperative aspiration was statistically similar regardless of the method of surgery.