Senior patients (people over 65 years old) are a large and constantly growing customer group in the medical imaging. To ensure pleasant experience for the customers, as well as the effective use of resources in the medical imaging departments, the patient education materials have to be clear and easily understandable. The aim of the study was to describe the essential features of written patient education materials in the context of senior customers. The goal was to provide the most recent knowledge in the field, on which the design of new patient education materials can be based. The study was conducted by qualitative method, namely literature research. Four databases available to Oulu University of Applied Sciences were searched for the most recent articles (published 2009-2014) about written patient education materials on the field of medical imaging. The search produced 88 results, which were screened based on the title, the abstract and the full text. The screening left two articles to be included into the study, which were further analyzed using theory-based content analysis. To secure the reliability of the study, the search and screening process was carefully documented. Based on the literature review it can be stated that overall the quality of the patient education ma-terials is on satisfactory level and they are considered to be clear and understandable. In the future also the patients should be included in the process of designing patient education materials and especially the needs of senior customers should be taken into consideration. There is a dearth of research on the written patient education materials and in the future the re-search should focus especially on radiology and the perspective of senior customers. This study was limited to the available databases and published research; hence, it would be beneficial to study empirically the patients’ perceptions of the written patient education materials in use.