The practice of interventional cardiology differs between countries and regions. In this study we report the results of the first nation-wide long-term comparison of interventional cardiology in two countries using a common web-based registry. The Swedish Coronary Angiography and Angioplasty Registry (SCAAR) was used to prospectively and continuously collect background-, quality-, and outcome parameters for all coronary angiographies (CA) and percutaneous coronary interventions (PCI) performed in Iceland and Sweden during one year. The rate of CA per million inhabitants was higher in Iceland than in Sweden. A higher proportion of patients had CA for stable angina in Iceland than in Sweden, while the opposite was true for ST elevation myocardial infarction. Left main stem stenosis was more commonly found in Iceland than in Sweden. The PCI rate was similar in the two countries as was the general success rate of PCI, achievement of complete revascularisation and the overall stent use. Drug eluting stents were more commonly used in Iceland (23% vs. 19%). The use of fractional flow reserve (0.2% vs. 10%) and the radial approach (0.6% vs. 33%) was more frequent in Sweden than in Iceland. Serious complications and death were very rare in both countries. By prospectively comparing interventional cardiology in two countries, using a common web based registry online, we have discovered important differences in technique and indications. A discovery such as this can lead to a change in clinical practice and inspire prospective multinational randomised registry trials in unselected, real world populations. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.