BACKGROUND: Pulsed dye lasers (PDLs) are considered the treatment of choice for port-wine stains (PWS). Studies have suggested broadband intense pulsed light (IPL) to be efficient as well. So far, no studies have directly compared the PDL with IPL in a randomized clinical trial. OBJECTIVES: To compare efficacy and adverse events of PDL and IPL in an intraindividual randomized clinical trial. METHODS: Twenty patients with PWS (face, trunk, extremities; pink, red and purple colours; skin types I-III) received one side-by-side treatment with PDL (V-beam Perfecta, 595 nm, 0.45-1.5 ms; Candela Laser Corporation, Wayland, MA, U.S.A.) and IPL (StarLux, Lux G prototype handpiece, 500-670 and 870-1400 nm, 5-10 ms; Palomar Medical Technologies, Burlington, MA, U.S.A.). Settings depended on the preoperative lesional colour. Treatment outcome was evaluated by blinded, clinical evaluations and by skin reflectance measurements. RESULTS: Both PDL and IPL lightened PWS. Median clinical improvements were significantly better for PDL (65%) than IPL (30%) (P = 0.0004). A higher proportion of patients obtained good or excellent clearance rates with the PDL (75%) compared with IPL (30%) (P = 0.0104). Skin reflectance also documented better results after PDL (33% lightening) than IPL (12% lightening) (P = 0.002). Eighteen of 20 patients preferred to receive continued treatments with PDL (P = 0.0004). No adverse events were observed with PDL or IPL. CONCLUSIONS: Both the specific PDL and IPL types of equipment used in this study lightened PWS and both were safe with no adverse events. However, the PDL conveyed the advantages of better efficacy and higher patient preference.