Purpose: There is little information about the efficacy of intravitreal vascular endothelial growth factor (VEGF) inhibition in vitrectomized eyes. This study aimed to evaluate the efficacy of anti-VEGF (ranibizumab) on diabetic macular oedema in previously vitrectomized eyes. Methods: A nationwide retrospective review of medical records from 2010 to 2013. Results: We identified 33 previously vitrectomized eyes in 28 patients treated with ranibizumab injections for diabetic macular oedema. Median follow-up was 323 days (interquartile range 72–1404 days). Baseline mean visual acuity was 0.57 logMAR (95% CI 0.13–1.01) before injections. After an average of 4.7 injections (range 1–15), mean visual acuity remained stable at 0.54 logMAR (95% CI 0.13–0.95) with a mean improvement of 0.03 (p = 0. 45, 95% CI −0.12 to 0.06). In 12 eyes (36%), visual acuity improved 0.1 logMAR or more, in 12 eyes (36%), vision was unchanged (gain or loss of 0–0.05 logMAR), and in nine eyes (27%), vision decreased 0.1 logMAR or more. Mean central foveal thickness (CFT) on optical coherence tomography (OCT) scan was 412 μm (95% CI 390–434 μm) before injections. After injections, the mean CFT decreased to 352 μm (95% CI 334–370 μm). The mean reduction in CFT was 14% (95% CI 4–24%, p = 0.01). Sixteen eyes (48.5%) became devoid of oedema on the last OCT scan. Despite the significant reduction in CFT, the visual acuity remained unchanged. Conclusion: Intravitreal ranibizumab can be effective in previously vitrectomized eyes with diabetic macular oedema. However, the response is variable and should be carefully monitored.