This retrospective study assesses the clinical features, treatment strategies, and long-term outcomes of patients with Coats' disease in Korea. Multimodal imaging and medical records of consecutive patients treated between July 2000 and April 2020 at two tertiary centers were evaluated based on onset age (adult vs. childhood [< 18 years]). Factors associated with final visual acuity (VA) and risk of treatment failure were assessed. A total of 71 eyes of 67 patients were included, with subgrouping by onset age showing 45% childhood and 55% adult cases. Overall, Stage 2 disease was most common at presentation (76%), though childhood cases had more Stage 3b (22% vs. 3%, P = 0.02) and greater clock hours of retinal telangiectasia (7 vs. 5, P = 0.005). First-line treatment included laser (25%), combined laser/anti-VEGF (23%), cryotherapy (20%), surgery (16%), and anti-VEGF only (9%). Cryotherapy was associated with a higher risk for secondary interventions (OR 11.8, P < 0.001), required in 56% overall. Despite a 3-line VA decrease in 34% overall, adult cases had superior final VA (P = 0.037). Multivariable regression showed that the number of anti-VEGF injections performed during the initial treatment period was associated with a 9.4 letter improvement in vision (P = 0.041). We observed a higher proportion of adult-onset Coats' disease than previously reported in other non-Asian populations. An aggressive treatment with the addition of anti-VEGF may yield the most favorable long-term visual outcomes.