Infantile hemangiomas (IH) complicated by ulceration, disfigurement, functional impairment or life-threatening conditions need early, safe and effective treatment. This study explores the impact of propranolol on complicated IH. We report our experience of 62 patients treated with oral propranolol for complicated IH. The effect of propranolol was assessed using a score on a visual analogue scale integrated with echo, magnetic resonance or endoscopic findings. The average age at the beginning of the treatment was seven months [standard deviation (SD)±8.9], with a median of four months (range 1-53 months). The average age at the end of the treatment was 15 months (SD±8.4), with a median of 13 months (range 7-59 months). The mean treatment length was eight months (SD±3.2). Oral propranolol was successful in 95.2% of the patients in reducing the volume, the intensity of color and the elevation of IH. Statistically significant improvement of IH volume was observed in the first two months of therapy (P≤0.001), and between the second month and the end of the treatment (P<0.05). No significant bradycardia or hypotension occurred. Severe hypoglycemia occurred in one patient. Mild adverse effects were observed in seven patients. Our study demonstrates that propranolol administered orally at 2 to 3 mg/kg/day has a rapid therapeutic effect leading to remarkable shortening of the natural course of IH and it is safe in the majority of patients.