Being listed as an author on a peer-reviewed paper or book chapter brings rewards, not only to the individual, but also to their research group and institution. But novice writers often ask who should be an author? The International Committee of Medical Journal Editors’ (ICMJE) definition of the roles and responsibilities of authors is widely accepted as the gold standard. However, the principles are often not well understood. Thinking through the ICMJE’s four criteria can greatly assist in dealing with the issue of authorship.