ActivEpi is an interactive self-learning software on epidemiology consisting of three major parts: objects and methods of epidemiologic research; validity of epidemiological research; epidemiologic analysis; and an appendix containing a reference guide to the statistical analysis program included in the CD, called Data Desk. ActivEpi provides a very valuable introduction into basic epidemiologic concepts. The program features many helpful details (e.g., a glossary, bookmarks) and practical examples. The contents are realized with high didactic standard, and working with the program is simply fun. The only drawback is Data Desk that is not very concise. Nevertheless, ActivEpi can be warmly recommended as an introductory epidemiological course or even for refreshing of details for more experienced scientists.