AIMS To determine the indications for penetrating keratoplasty (PK) at the Corneoplastic Unit and Eye Bank, UK, a tertiary referral centre, over a 10 year period. METHODS Records of all patients who underwent PK at our institution between 1990 and 1999 were reviewed retrospectively. Of the 1096 procedures performed in this period, 784 records were available for evaluation (72%). RESULTS Regrafting was the most common indication, accounting for 40.9% of all cases. Keratoconus was the second most common indication (15%), followed by Fuchs' endothelial dystrophy (9.3%), pseudophakic bullous keratopathy (7.6%), and viral keratitis (5.9%), which included both herpes simplex and herpes zoster and showed a statistically significant decreasing trend using regression analysis (p<0.005). Among the regraft subgroup, viral keratitis accounted for 21.2% as the underlying primary diagnosis. The most common cause for graft failure in the regraft subgroup was endothelial failure (41.8%). CONCLUSION Regrafting is the leading indication for PK; viral disease-although declining-is the leading primary diagnosis.