AIM: To investigate the clinical features of newly diagnosed diabetes mellitus (NDM) patients showing proliferative diabetic retinopathy (PDR) as an initial sign.METHODS: As a retrospective case series, the medical records of a total of four hundred and thirty-two patients who underwent a vitrectomy due to PDR were reviewed to find the subjects. Of 432 patients, six cases of NDM patients showing PDR as an initial sign were included and analyzed with their systemic and ocular features. Main outcome measures:the systemic features and ocular features [preoperative and postoperative best corrected visual acuity (BCVA), intraoperative findings].RESULTS: The mean onset age of visual symptoms was 36.3 years old. The mean serum insulin and C-peptide titer was below the normal range. The mean fasting plasma glucose was 178mg/dL and the mean postprandial 2h plasma glucose was 306mg/dL. The mean HbA1c at diagnosis was 11.02%. In all cases, an acute progressive fibrovascular proliferation was observed. Intraoperative retinal tears were found in three cases of six. The mean preoperative BCVA was +0.67±0.58 logMAR and the mean BCVA at postoperative 6 months was +0.20±0.30 logMAR.CONCLUSION: All patients were considered to have latent autoimmune diabetes in adults (LADA). A rapid deterioration of kidney function as well as poor diabetic control status at diagnosis was observed in all six cases. The ocular features of the patients showed acute progressive fibrovascular proliferation and relatively favorable postoperative visual acuity.