At Great Ormond Street Hospital for Children NHS Trust, Pulsed Dye Laser (PDL) therapy is the first line laser treatment for port wine birthmarks (PWB). For recalcitrant PWB, we use triple wavelength therapy using Multiplex laser which is a combination of PDL 585 nm and Nd: YaG 1064 nm, superimposed by PDL at 595 nm five minutes later. Known complications following laser therapy are pain, redness, and bruising, however, scarring is very rare. In this the study we were keen to determine and publish the incidence and the possible risk factors associated with perioral scarring as a complication of laser therapy. A single centre retrospective observational study was performed amongst children aged 3–18 years with facial and perioral PWB who were treated with laser therapy. Patients who were treated for other facial vascular anomalies were excluded from the study. A total of 139 patients with perioral PWB were treated with laser from January 2019 to January 2022. The incidence of perioral scarring after laser treatment was 4.3% (6 patients) over a 3-year period. We found that the key risk factors for scarring were use of multiplex laser (particularly Nd: YaG), inadequate post-operative nursing care, lack of parental education, abnormal wound healing, and equipment failure with improper delivery of cooling. We concluded that the use multiplex laser (particularly Nd: YaG) entails a higher risk for peri-oral scarring. The perioral area is more vulnerable to complications and scarring from laser treatment, because the dermis in this area is thin and sensitive. The complications from laser therapy can be minimised by early recognition of pre-scarring signs, nursing advice and early treatment.