Post-procedure purpura is a major complaint of patients with port-wine stains (PWSs) treated with pulsed dye laser (PDL). To assess the safety and efficacy of using PDL at nonpurpuric settings to treat ecchymoses that develop within PWSs after treatment with PDL. Prospective, randomized, controlled study using 595-nm PDL for treatment of PWSs and laser-induced ecchymoses. Port-wine stains were treated in entirety at baseline. Two days later, ecchymoses on randomly selected half of the lesion were re-treated with PDL at subpurpuric settings. Treatment series was repeated 4 to 8 weeks later, and follow-up was at 1 month. Reduction in bruising and PWS clearance were assessed. Three masked evaluators graded clinical improvement using a 4-point scale (1 = 1%-25% improvement, 2 = 26%-50% improvement, 3 = 51%-75% improvement, and 4 = 76%-100% improvement). Twenty adults with 21 PWSs on the head, trunk, and extremities were treated. After first treatment, reduction of bruising was graded a mean value of 2.43 for the treatment side, compared with 1.93 for the control side (p = .012); after the second treatment, 2.83 compared with 2.40 (p = .021). No significant adverse events occurred. Pulsed dye laser can be used safely and effectively to reduce treatment-induced purpura in patients with PWSs.