Purpose.To report a case of postoperative endophthalmitis after combined cataract extraction and iStent inject implantation.Observation.A 70-year-old male with a nuclear sclerotic cataract and primary open-angle glaucoma underwent an uneventful phacoemulsification cataract extraction with implantation of an intraocular lens and an iStent inject trabecular bypass stent. The patient was prescribed a postoperative regimen of ofloxacin 0.3% and prednisolone acetate 1%, 1 drop four times a day each. On postoperative day five, he presented to the emergency room for eye pain and had 4+ mixed cells in the anterior chamber (AC) without hypopyon or vitritis on exam. Prednisolone 1% eye drops were increased from four times a day to every two hours while awake. Overnight, he developed worsening vision and severe eye pain. The next morning, he was found to have increased AC cells, vitritis, and intraretinal hemorrhages and was diagnosed with endophthalmitis. The patient underwent a vitreous tap and intravitreal injections of vancomycin (1 mg/0.1 mL) and amikacin (0.4 mg/0.1 mL). Cultures grewStaphylococcus epidermidis. Lab work-up revealed underlying neutropenia. Visual acuity eventually recovered to 20/20.Conclusion and Importance.This report highlights a case of endophthalmitis associated with placement of the iStent inject. The infection was well-controlled after administration of intravitreal antibiotics without removal of the iStent inject, and visual acuity eventually recovered to 20/20. Surgeons should be aware of endophthalmitis risk following combined iStent inject placement, and good recovery is possible without removal of the implant.