Intraocular infections associated with Abiotrophia defectiva are rare. This article reports the case of a 57-year-old woman with endophthalmitis associated with Abiotrophia defectiva 3 months after uncomplicated cataract surgery combined with the implantation of a glaucoma gel-stent in the right eye. The patient had complained of redness of the right upper nasal conjunctiva and pain for 2 weeks prior to the endophthalmitis. A topical steroid eyedrop treatment without antibiotic additives had temporarily improved the situation. The patient presented with hypopyon, acute deterioration of vision and severe periocular pain of the right eye since the early morning. The gel-stent had spontaneously perforated the conjunctiva. The patient was immediately started on local and systemic antibiotics and underwent pars plana vitrectomy with intravitreal antibiotic application 6 h after presentation. Unlike other ocular infections with Abiotrophia defectiva, this case had a relatively benign course most likely due to the prompt intervention. In clinical routine, patients, who present with acute deterioration of vision and pain after glaucoma surgery, should be examined urgently considering a possible spontaneous conjunctival perforation and late onset endophthalmitis. Additionally, conjunctivitis of unclear origin following ocular surgery should always be treated with antibiotics, particularly when steroids are administered and monitored closely.