To report an unusual toxoplasma chorioretinitis presenting a macular branch retinal arterial occlusion adjacent to the active chorioretinitis lesion.

An unusual toxoplasma chorioretinitis presenting a macular branch retinal arterial occlusion adjacent to the active chorioretinitis lesion is reported in a 45-year-old Iranian woman awoke 2 days before examination with decreased visual acuity and superior visual field defect in the left eye.

Ocular toxoplasmosis can cause a variety of retinal vascular changes including branch retinal arterial occlusion, which is a rare complication of the disease. The patient received an appropriate steroid and antibiotic treatment, and the retinitis lesion resolved over a 6-week period. At 2 months after diagnosis, visual acuity in her left eye was 20/30 and there was a hyperpigmented scar at the site where active retinitis had been observed.

As this branch vascular obstruction may change the appearance of the fundus and obscure the initial inflammatory focus, ocular toxoplasmosis should be included in the differential diagnosis of branch retinal vascular occlusion associated with posterior uveitis, particularly in young patients.