PURPOSE: Different modes of photodynamic therapy (PDT) were described for treatment of central serous chorioretinopathy (CSC). The purpose of the current study was to evaluate the outcome of half-time PDT in chronic CSC. METHODS: A retrospective case series study, including 114 eyes of 103 patients with chronic CSC, treated with reduced-fluence PDT. PDT was applied with full-dose verteporfin (6 mg/m) and half-time fluence (43 s). The main outcome measures included timing of complete subretinal fluid (SRF) resolution, recurrences, pre- and post-treatment best-corrected visual acuities (BCVA). Anatomical and functional effects were compared in subgroup analysis on the basis of CSC treatment efficacy. Subsequent analysis was performed to compare eyes with and without recurrences and CSC eyes treated by single and multiple PDT sessions. RESULTS: A total of 114 eyes of 103 patients (81 male; 22 female) were analyzed. The median age was 49 (28-70). The median CSC pretreatment duration was 12 months (3-393). The median follow-up period after PDT was 8 months (6-111). By the sixth-month period PDT was effective in 80% (91 eyes), with a subsequent enhancement up to 87% (99 eyes) at 12th month and not effective in 13% (15 eyes). SRF resolution was achieved after 8 weeks (2-44) with a significant improvement of median LogMAR BCVA from 0.22 (- 0.2-1.3) before PDT to 0.1 (- 0.2-1.0) at last visit after PDT (p < 0.0001). CONCLUSIONS: Half-time PDT has proven to be an effective and safe treatment option for patients with chronic CSC with a significant BCVA improvement during the follow-up after the therapy.