OBJECTIVE To determine the safety and efficacy of implanting a second intraocular lens (IOL) to correct myopic pseudophakic refractive error after penetrating keratoplasty (PKP). METHODS Department of Ophthalmology, Toronto Western Hospital, Toronto, Ontario, Canada. METHODS In this retrospective case series, 6 eyes of 6 post-PKP pseudophakic patients had a second piggyback IOL implantation to correct a residual myopic refractive error. The uncorrected visual acuity (UCVA) and the best corrected visual acuity (BCVA) were measured at regular intervals during a 7-month follow-up. Efficacy was determined by the achieved refractive correction and Snellen UCVA measurements. Safety was measured by loss of BCVA and complications (intraoperative and postoperative). RESULTS The UCVA improved in all cases. Five patients achieved a BCVA of 20/40 or better postoperatively. Before surgery, the mean spherical equivalent (SE) was -8.08 diopters (D) (range -6.13 to -12.00 D). After surgery, the mean SE was -0.94 D (range -2.38 to +0.25 D). Four patients were within +/-1.50 D of emmetropia. There were no intraoperative or postoperative complications. CONCLUSIONS Implanting a piggyback IOL was a safe and effective means of correcting myopic pseudophakic refractive error post PKP.