PURPOSE: To report short-term regression of neovascularization after varying intravitreal doses of bevacizumab (Avastin®; Genentech, San Francisco, California, USA) in patients with proliferative diabetic retinopathy (PDR).METHODS: Eighty eyes from 76 patients with active neovascularization of the disc (NVD) or elsewhere (NVE) caused by PDR were divided into four groups and treated with a single intravitreal bevacizumab (IVB) injection of 1.25 mg, 600 μg, 300 μg or 150 μg, respectively. All patients underwent ophthalmoscopic examination and fluorescein angiography at baseline, 1 week, 1 month and 2 months later.RESULTS: No significant ocular or systemic adverse events were observed. In all patients with NVD or NVE, complete resolution of leakage was recorded within the first week or the first month of the injection. Even with the lowest dose (150 μg), regression of neovascularization appeared as early as the first week and lasted for over a month. Recurrence of fluorescein leakage was observed in all groups after the first month and did not correlate with the extent of neovascularization or IVB dose.CONCLUSION: Short-term results suggest that IVB given below the standard dosage (150–300 μg compared to 1.25 mg) can lead to the achievement of complete regression of diabetic retinal neovascularization within 30–45 days of injection.