Corneal transplantation to restore vision is known from earlier times. In penetrating keratoplasty (PKP), the entire thickness of the recipient’s cornea is replaced with donor cornea. PKP is the most commonly performed transplant procedure. The indications for PKP can be classified into two general categories: (1) decreased vision due to corneal opacification or corneal irregularity and (2) any corneal condition that is likely to cause loss of the eye. Donor corneas are obtained by either enucleation or corneal excision usually performed by an eye bank technician or trained paramedical personnel. A comprehensive informed consent is undertaken from the patient who is a candidate for a PKP about what to expect postoperatively and about whether to undergo such a procedure. PKP is usually performed as an outpatient procedure. The technique of PKP and complications (intraoperative and postoperative) are explained in detail.