Treatment of infantile hemangiomas with pulsed dye laser is controversial because of their natural history of spontaneous involution. We retrospectively evaluated treatment results and complications of 36 hemangiomas treated with long-pulsed dye laser in 31 patients aged 1-3 months. The hemangiomas were classified into superficial type and mixed type by clinical appearance. The mean numbers of treatment were 6.6 (range : 1-18) in the superficial type, and 15 (range : 7-25) in the mixed type. In 44% of all hemangiomas, the treatment resulted in complete clearance. Minimal residual signs and apparent residual signs were seen in 44% and 11% of the superficial and mixed types hemangiomas, respectively. The long-pulsed dye laser treatment was more effective in the superficial type than in the mixed type. The main complications were hyperpigmentation (22%) and hypopigmentation (6%). No patient experienced infection, bleeding, ulceration, skin atrophy or scar formation. In conclusion, we recommend early treatment with long-pulsed dye laser for infantile hemangiomas because this therapy is effective and safe.