Purpose To report the safety and efficacy of simultaneous bilateral 25-gauge lens-sparing vitrectomy for vascularly active stage 4 retinopathy of prematurity (ROP). Methods Retrospective, noncomparative, consecutive case series. Twenty eyes of 10 babies who presented with vascularly active stage 4 ROP in both the eyes underwent simultaneous bilateral 25-gauge lens-sparing vitrectomy. After completing surgery for one eye, the other eye was re-prepped as performed before starting any new case of a different patient and an entire new set of disposable 25-gauge instruments were used. During the post-operative period parents were advised to keep separate eye drops for each eye and to wash their hands in between switching the eyes to put the drops. Results The mean follow-up was 8.7 months (range 4-17 months). None of the cases developed any signs of infection. The anatomic success rate for stage 4a was 100% (11/11 eyes) and for stage 4b was 8/9 eyes (89%). Conclusion These results show that simultaneous bilateral 25-gauge lens-sparing vitrectomy for stage 4 ROP is a safe and effective procedure with a good outcome provided both eyes of the baby are treated as eyes of two different patients.