Background: Primary antiphospholipid syndrome (PAPS) is a thrombotic condition which characteristically includes ocular vaso-occlusive pathology.Case: We present the case of a 47-year-old woman with PAPS presenting with retinal vascular leakage.Observations: Vascular leakage was an incidental finding on fundoscopy in a myopic Chinese woman, and initially this was diagnosed as diabetic retinopathy. However, a glucose tolerance test was negative. Subsequently, signs of retinal vaso-occlusion developed. Previous subclinical cerebral thrombosis, mild thrombocytopaenia and positive tests for antiphospholipid antibodies were consistent with the diagnosis of PAPS. Anticoagulation therapy with warfarin prevented further thrombotic episodes.Conclusion: The possibility of PAPS should be considered in patients presenting with retinal vascular disease without obvious vascular risk factors.