Purpose To investigate the long‐term outcomes of patients who underwent vitrectomy for proliferative diabetic retinopathy. Methods Cumulative incidences were calculated for low vision (<0.3), re‐vitrectomy in the study eye and fellow eye vitrectomy. To identify potential prognostic factors that associate with these outcomes, we used multivariable Cox regression models. Results In a total of 217 patients, we found 1‐, 5‐ and 10‐year cumulative incidences of low vision in the study eye of 24%, 31% and 39%, respectively. For both eyes, these rates were, respectively, 10%, 14% and 14%. Low vision in both eyes was associated with higher age and worse contralateral visual acuity. The 1‐, 5‐ and 10‐year cumulative incidences for re‐vitrectomy in the study eye were 16%, 27% and 27%, respectively, and for a vitrectomy in the fellow eye 24%, 40% and 54%, respectively. Re‐vitrectomy of the study eye was associated with worse contralateral visual acuity, while vitrectomy of the fellow eye was associated with shorter diabetes duration, worse contralateral visual acuity, higher HbA1c level and worse diabetic retinopathy severity stage of the fellow eye. Conclusion Functional visual acuity in at least one eye was achieved or preserved in most patients. After 10 years, about a quarter of all patients underwent a re‐vitrectomy, while more than half of the patients needed a vitrectomy of the fellow eye. Knowledge of these long‐term outcomes is essential when counselling patients for a vitrectomy.