Purpose: To evaluate the surgical outcome of therapeutic penetrating keratoplasty (TPK) done for resistant corneal infection not responding to medical treatment. Setting: Memorial institute for ophthalmic research Method: A retrospective case series study included 20 cases of the therapeutic penetrating keratoplasty done for patients with resistant progressive corneal microbial infection not responding to aggressive topical treatment at Memorial institute for ophthalmic research in Egypt between 2019-2021. Evaluation included the eradication of infection, restoration of globe integrity, rate of recurrence, and visual outcome 1 year postoperatively. Results: The anatomical integrity of the eye was restored in 18/20 cases (90%). Recurrence occurred in three cases (15%). Regarding the visual outcome,50% of the cases had corrected visual acuity between 0.05-0.6 in decimal while 35% had hand motion vision due to cataract, graft opacity or recurrence. Seven patients required an adjunctive surgical procedure: one underwent re-PKP, one required evisceration and five required cataract surgery. Conclusion: Therapeutic penetrating keratoplasty done for resistant progressive microbial keratitis is a valuable treatment for eradication of infection, restoring anatomical integrity of the eye. Early TPK provides better surgical and visual outcomes.