The aim of this study was to examine and describe how nursing students developed their reasoning and knowledge about the state of health of, and their possible actions regarding, two fictitious elderly patient case histories during their three-year education. The descriptions were audiotaped, transcribed verbatim and analysed by content analysis. The findings show a development in the students' reasoning concerning the more acute case, but no development in reasoning regarding the case of a confused person. This could be due either to a lack of education in gerontology and geriatrics, or to the students receiving limited guidance during their education on how to reason about and reflect upon different ways of approaching emerging problems. The findings could also be understood in the light of traditions and history in nursing education.