Corneal opacitiesCorneal opacities can cause severe and permanent impairment of the visual acuity if centrally located. Homologous penetrating keratoplastyKeratoplasty (HPK) is usually the standard therapeutic option to treat patients with such clinical conditions. However, autologous penetrating keratoplastyKeratoplasty (APK) can sometimes be a more suitable alternative depending on the clinical presentation, the patient’s compliance and even the infrastructural and geographical situation, without risk of immunological graft rejectionGraft rejection. This chapter summarizes the topic of autologous penetrating keratoplastyKeratoplasty (APK), and reports surgical techniquesTechnique, indicationsIndication and (dis)advantages of two subtypes of APK: ipsilateral rotationalIpsilateral rotational autologous keratoplasty and contralateral APK. In ipsilateral rotationalIpsilateral rotational autologous keratoplasty APK, an eccentric trephinationTrephination is performed, whereby a central corneal opacityCorneal opacities lies at the edge of the excision margin. The corneal button is then rotated, bringing the scar toward the limbus and the clear corneaCornea towards the visual axis. A contralateral APK could be performed in a more particular clinical presentation with a central corneal opacityCorneal opacities in a functionally better eyeEye with good visual prognosis, and a clear corneaCornea in the nearly blind fellow eyeEye with poor or no visual prognosis. During this procedure, the clear corneaCornea from the (nearly) blind eyeEye with a non-corneal pathology is transplanted into the potentially better-seeing eyeEye with the corneal pathology. As part of this procedure, a HPK must first be performed in the (nearly) blind donor eyeEye. The option of an autologous penetrating keratoplastyKeratoplasty (APK) should always be considered in particular clinical situations before corneal microsurgeons move on directly towards homologous keratoplastyKeratoplasty (HPK).