This cohort study included 36 eyes of 21 patients with high myopia treated with angle supported phakic intraocular lens (pIOL). Endothelial cell density (ECD) at baseline, 6mo and 3y were 3017±296, 2775±265 and 2558±299 cells/mm2 respectively. ECD loss at 6mo was 7.2% and annual ECD loss was 3% over 36mo. Corrected distance visual acuity at 36mo was 0.4 logMAR or better in 32 (88.9%) eyes. Intraocular pressure did not change (P=0.9). No eyes developed cataract, retinal detachment or pupillary distortion. Angle supported pIOL gives good visual outcome. Endothelial cell loss should be monitored.