Hematoporphyrin monomethyl ether (HMME) is a newly authorized photosensitizer for the treatment of port-wine stain (PWS) in China. However, no research on its efficacy for treating PWS lesions of Sturge-Weber syndrome (SWS) has been made. To assess the efficacy and safety of HMME-PDT in the treatment of SWS and simple large segmental facial PWS. Medical records of patients with SWS and large segmental facial PWS were reviewed. Efficacy was evaluated according to colour blanching and graded as excellent (≥75%), good (50-74%), fair (25-49%), and poor (≤24%). Adverse events were analysed. 19 patients with SWS and 33 patients with large segmental facial PWS were analysed. 52.6% SWS and 69.7% PWS patients (P>0.05) achieved at least 25% improvement. Common adverse events included short-term pain, edema, pruritus, exudation, and scab. No severe adverse event occurred. HMME-PDT was effective and safe for SWS and large segmental facial PWS. This article is protected by copyright. All rights reserved.