Background: Lung cancer is the leading cause of cancer-related death in all Nordic countries which, though similar in demographics and healthcare systems, have noticeable differences in lung cancer survival. Historically, Denmark and Finland have had higher lung cancer incidences and lower survival than Norway and Sweden. All four countries have national cancer registries. Data in these registries are often compared, but their full potential as a source of learning across the Nordic countries is impeded by differences between the registries. In this paper, we describe and compare the Nordic registries on lung cancer–specific data and discuss how a more harmonized registration practice could increase their usefulness as a source for mutual learning and quality improvements. Methods: We describe and compare the characteristics of data on lung cancer cases from registries in Denmark, Finland, Norway and Sweden. Moreover, we compare the results from the latest annual reports and specify how data may be acquired from the registries for research. Results: Denmark has a separate clinical lung cancer registry with more detailed data than the other Nordic countries. Finland and Norway report lung cancer survival as relative survival, whereas Denmark and Sweden report overall survival. The Danish Lung Cancer Registry and the Swedish Cancer Registry do not receive data from the Cause of Death registries in contrast to the Finnish Cancer Registry and the Cancer Registry of Norway. Conclusion: The lung cancer registries in Denmark, Finland, Norway and Sweden have high level of completeness. However, several important differences between the registries may bias comparative analyses.