Readability and usability problems with patient information leaflets continue to be reported despite long-standing recognition of their existence and the availability of guidelines for developing health education materials. This exploratory study examined possible causes for such problems, based on interviews with professionals who developed leaflets in large health organizations. Findings suggest that readability is an important concern for developers, but that complex organizational processes are involved in creating leaflets, and that developers face a need to cope with organizational politics, goal conflicts and various other pressures. Six factors were identified, i.e. (1) initiators, (2) intended users and contexts of use, (3) goals, (4) work flow and content decisions, (5) readability considerations, and (6) evaluation practices, that can adversely affect the content, organization, and resulting comprehensibility and usability of leaflets. It is suggested to adopt a broad ecological view of the environments in which patient education materials are created and deployed. Implications for practice and for future related research are discussed. (Contains 1 table.)