Background To describe a rare case of vein occlusion and vitreous hemorrhage as complications of prepapillary arterial loop. In this report, sinusitis was recognized as an uncommon cause of bleeding from this optic disc abnormality. Case presentations: A case of a-33-old-man suffering from acute sinusitis and presented with vitreous hemorrhage. Etiologic investigations were normal. Fundus examination and angiography confirmed the diagnosis of prepapillary arterial loop and a mild peripheral vein occlusion. Good prognosis was noted after the treatment of sinusitis and water drink. Conclusions Sinusitis should be considered as a possible trigger factor of bleeding from prepapillary loops in any healthy young patient. An early treatment of the sinus inflammation may lead to a good prognosis.