Objective To analyze the causes of misdiagnosis of acute retinal necrosis syndrome (ARN),and possible critical points in preventing misdiagnosis.Methods Clinical data of 81 cases (93 eyes) in-patients with ARN from May 2006 to May 2012 in Zhongshan Ophthalmic Center,Sun Yat-sen University were retrospectively analyzed.Results The average time of first visit after appearance of ocular symptoms was 7.03 days (1 to 21 days),86 eyes (91.36％) was misdiagnosed in total.There were only 7 eyes that were correctly diagnosed at initial ophthalmic consultation.It took 31.11 days (ranging from 5 to 280 days) to reach the correct diagnose.Among the misdiagnosed eyes,22 eyes (29.73％) experienced one time misdiagnosis,35 eyes (47.3％) twice and 17 eyes (22.97％) had correctly diagnosis after three or even more time of ophthalmic examinations.Of the 86 misdiagnosed eye,55 eyes (63.95％) was labeled as uveitis,27 eyes (31.40.％) as kidocyclitis,28 eyes (32.55％) as other without explicit type of uveitis.Fifteen eyes (17.44％) were as conjunctivitis and 3 eyes (3.49％) as glaucoma and 13 eyes (15.12％) as others such as retinitis,Eales disease,retinal artery occlusion and retinal hemorrhage.Conclusions ARN is a easily misdiagnosed severe eye diseases.Ophthalmic professional have be alert when come across various uveitis and retinal diseases.