To evaluate the efficacy of photodynamic therapy (PDT) after 1/3 dose verteporfin injection to treat acute central serous chorioretinopathy (CSC). METHODS: Twenty-six eyes of 26 cases diagnosed with acute CSC by fundus fluorescein angiography(FFA) and optical coherence tomography (OCT) examination received one single session of PDT using 1/3 dose (2mg/m2) verteporfin. Best-corrected visual acuity (BCVA) was measured before, 1 week, 4 weeks, and 12 weeks after PDT with 1/3 dose. OCT, FFA and indocyanine green(ICG) examination were performed before, 4 weeks, and 12 weeks after PDT with 1/3 dose. RESULTS:Twenty of 26 eyes (77%) had complete resolution of subretinal fluid (SRF) 1 week after 1/3 dose PDT treatment. After 4 weeks, SRF in 26 eyes was completely absorbed, fluorescein leakage of 22 eyes reduced in FFA and the tortuous choroidal vessels appeared normal in ICG; Twelve weeks after PDT, there was no recurrence of CSC in 26 eyes. The mean BCVA was improved from 0.41 to 0.80 1 week after PDT treatment. CONCLUSION: PDT with 1/3 dose verteporfin injection is effective and safe in treating acute CSC