PURPOSE: To compare the efficacy of half-dose vs half-time photodynamic therapy (PDT) guided by fluorescein angiography (FA) for the treatment of central serous chorioretinopathy (CSC). DESIGN: Two-center, retrospective, comparative case series. METHODS: Sixty-one eyes with acute or chronic CSC involving fovea were recruited; 35 eyes received half-dose PDT and 26 eyes received half-time PDT. Improvement in best-corrected visual acuity (BCVA), resolution of subretinal fluid (SRF) demonstrated by optical coherence tomography (OCT), and recurrence of CSC after PDT were compared between the 2 groups. RESULTS: The mean follow-up time after PDT was 14.8 ± 13.3 months. Both groups showed significant improvement in BCVA at months 1, 3, 6, and 12 after PDT (P < .05 for all times). Multiple regression analysis showed that PDT type was not correlated with visual improvement (P > .05 for all times). All eyes that received half-time PDT showed complete resolution of SRF within 6 months after PDT, but 3 eyes that received half-dose PDT had persistent SRF before loss to follow-up at months 5, 7, and 8 (P = .21 between 2 groups). Three of 32 eyes in the half-dose group and 2 of 26 eyes in the half-time group had recurrence of CSC during follow-up; all recurrent cases had complete SRF resolution after another PDT treatment. No adverse systemic or ocular side effects were observed in any cases. CONCLUSIONS: Half-dose and half-time FA-guided PDT were both effective and safe in treating CSC and showed similar efficacy in visual improvement and SRF resolution.