Objective To evaluate the clinical features and treatment outcomes of ocular posterior segment syphilis. Methods The clinical data of 24 patients with active ocular syphilis were retrospectively reviewed. The diagnosis was made first in eye clinic，and verified by treponema pallidum particle agglutination (TPPA) and rapid plasma reagin (RPR). The patients, 17 males and 7 females, aged from 30 to 63 years with an average of 47.6 years. The duration of symptoms ranged from 3 days to 2 years with an average of 5.8 months (le;1 month, 7 cases; 1-3 month, 5 cases; 3-6 months, 5 cases; ＞6 months, 7 cases). There were 18 bilateral cases and 6 unilateral cases. The result of human immunodeficiency virus (HIV) test was negative for all cases. Twenty-three patients received systemic penicillin therapy and 1 patient was treated with oral erythromycin due to penicillin allergy. Before treatment, the mean visual acuity was 0.17plusmn;0.19，the mean titer of RPR was 1:84。The follow-up period was half a year. Results The major ocular manifestations included bilateral (16 cases) or unilateral (1 case) chorioretinitis, unilateral retinal vasculitis (2 cases), unilateral neuroretinitis (2 cases), and bilateral (2 cases) or unilateral (1 case) optic neuritis. The mean follow-up visual acuity was 0.60plusmn;0.29，the mean follow-up titer of RPR was1:18.8. Some patients had got the diagnosis and prompt treatment at the early stage of the disease and their visual acuity recoveried very well. Conclusions The major manifestion of ocular posterior segment syphilis is chorioretinitis. It is important to consider the possibility of syphilis when patients have inflammation of posterior segment. Prompt serology examination and penicillin treatment are the keys to cure ocular syphilis.