The author treated 456 cases of port-wine stains using a tunable dye laser (577-nm wavelength, 1-microsecond pulse, 2-3-mm diameter spot), and followed up 22 cases for a year or more after the initial treatment. The treatment was regarded as effective in 80.5% of the abnormal lesions. The results were influenced by location: good results were achieved in the neck region and face, but results in the extremities were poor. The dye laser can achieve selective injury to abnormal vessels of port-wine stains while inflicting less damage to the overlying dermis than the argon laser. Therefore, dye laser treatment for port-wine stains is more effective than argon laser treatment.