Background: Current guidelines in cardiology training programs recommend 100-300 coronary angiography procedures for certification. We aimed to assess the number of procedures needed to reach sufficient proficiency. Methods: Procedure time, fluoroscopy time, dose area product (DAP), and contrast media volume were used as indicators of quality of performance. We analyzed data from 4,200 coronary angiographies. Performance curves of seven trainees were compared with recommended reference levels and to those of seven interventional cardiologists. Results: On average, the number of procedures needed for trainees to reach recommended reference levels was estimated as 226 and 353, for DAP and use of contrast media, respectively. After 300 procedures, trainees' procedure time, fluoroscopy time, DAP, and contrast media volume were significantly higher compared with experts' performance, P <0.001 for all parameters. To approach the experts' level of DAP and contrast media use, trainees need 394 and 588 procedures, respectively. Performance curves showed large individual differences in the development of competence. Conclusion: On average, trainees needed 300 procedures to reach sufficient level of proficiency, and this is in accordance with current guidelines. However, because of large individual differences, performance curves might be useful in monitoring individual trainees' progress and ensure documentation of sufficient competence when dealing with patients at risk. © 2011 Wiley-Liss, Inc.