The copper vapour laser has in theory qualities which make it interesting in the treatment of cutaneous vascular malformations. In order to study the clinical effect of the copper vapour laser and to compare its effect with the effect of the argon laser, we treated 38 patients with port-wine stain or facial telangiectasia with the copper vapour laser. Thirty-one patients were evaluated and of these 24 were improved or much improved. Nineteen patients had previously been treated with the argon laser, and in this group the copper vapour laser had better effect than the argon laser in 8 patients and equal effect in 9 patients. In 7 patients side-effects like scarring or hyperpigmentation were noted after treatment with copper vapour laser.