To report the clinical and microbiological characteristics of infectious endophthalmitis after Boston type I keratoprosthesis (B-K-Pro) implantation. Retrospective analysis of 136 eyes that received a B-K-Pro type 1 between 1999 and 2012 was performed. Five eyes with a diagnosis of exogenous endophthalmitis after B-K-pro type 1 were identified and information about demographic data, indication for K-Pro, post-operative bandage contact lens use, post-operative prophylactic antibiotic use, timing and clinical presentation of endophthalmitis, gram stain and culture results of intraocular fluid and preoperative and post-operative visual acuity were collected. The incidence of endophthalmitis was 3.67% (5 of 136 eyes) and average time to develop endophthalmitis was 5.62 months (range 2 days to 8 months). Mean patient age was 31.4 years (5 to 65 years). The surgical indications included corneal injury due to chemical burns (n = 2), multiple failed grafts secondary to microbial keratitis (n = 2) and congenital glaucoma with congenital herpetic keratitis (n = 1). Post-Boston K-Pro, the visual acuity ranged from light perception (LP) to 20/50. K-pro was explanted in 4 patients. There was bacterial and fungal growth in two patients each and one vitreous did not grow anything. All the eyes were phthisical at last visit. Infectious endophthalmitis after K-Pro implantation in our study had a higher incidence, early onset and extremely poor visual outcome compared with post-cataract surgery endophthalmitis, as reported in literature. Not only bacterial but also fungal infections are an important etiology for infectious endophthalmitis in these cases.