AIMS: To demonstrate variations in posterior capsule rupture (PCR) rate between surgeons of the same and different grades as a by-product of routine clinical care. METHOD: NHS departments using electronic medical record (EMR) systems to collect the Cataract National Dataset (CND) were invited to submit data. Data were remotely extracted, anonymised, assessed for conformity and completeness, and analysed for rates of PCR for individual surgeons within each of the three grades. RESULTS: Data were extracted on 55,567 cataract operations performed at 12 NHS trusts by 406 surgeons between November 2001 and July 2006. Data on the grade of 404 of the 406 surgeons who contributed to the study were available for 55,515 cases (99.9%) and were used for this analysis. Variation in PCR rate between surgeons was highest for the most junior grade of surgeon and between those surgeons contributing relatively few cases to the data set. Variation in PCR was lowest among experienced surgeons contributing large numbers of cases to the data set. CONCLUSIONS: Considerable variation in PCR rate exists both between and within surgical grades. Routine electronic collection of the CND allows detailed analysis of variations in PCR rates between individual surgeons. To define acceptable limits for this benchmark complication of cataract surgery, further work is needed to adjust surgeons' outcomes for the case mix complexity.