Purpose To evaluate the efficacy of early pars plana vitrectomy (PPV) and silicone oil (SO) tamponade for treating acute post-phacoemulsification infectious endophthalmitis. Methods This retrospective study included 44 eyes of 44 patients who developed early endophthalmitis after uneventful phacoemulsification. PPV with SO tamponade was performed within 24 h of presentation. Results A significant improvement in logMAR visual acuity (VA) was reported in our patients; (2.595 ± 0.249 at baseline compared to 1.052 ± 0.462 at final visit), with P value 0.0001. SO was removed in all cases after 4–9 months (6 ± 1.3) and all patients continued follow-up for at least 6 months after SO removal (15.4 ± 6.5). Postoperative complications included; three eyes (6.8%) developing severe proliferative vitreoretinopathy (PVR), four eyes (9.1%) developing inferior retinal detachment (RD) under SO, Two eyes (4.5%) developing pupillary block glaucoma and two eyes (4.5%) suffered from recurrent RD after SO removal. Conclusion Early PPV with SO tamponade for the treatment of acute endophthalmitis after phacoemulsification has good visual outcomes and lower complication rates if performed early within 24 h of patient presentation