Introduction. The literature shows that nurses have an important role to play in sleep promotion. There is a lack of literature which has set out to investigate what nurses know or feel about sleep promotion or how they are prepared for this role. Aims. This study explored the educational experiences, knowledge and attitudes of student and registered nurses regarding sleep promotion. Design. A mixed method approach which was partly informed by the principles of ethnography was used. It was carried out over time in 4 phases. Methods. 1. Quantitative descriptive data on sleep input in pre-registration nursing Higher Education Institutions (HEIs) (n=27) collected by postal survey. 2. Questionnaires completed by student volunteers from 4 HEIs (n= 120) in the last 6 months of their nursing programme and by registered nurse volunteers from critical care and care of the elderly backgrounds studying at 4 HEIs (n=98). 3. Interviews carried out with a sample of the students (n=26) and the registered nurses (n=15). 4. Further interviews with 16 of the original students, 6 -12 months post-qualification. Results. The findings showed that there was no standardisation of educational input in the HEIs. The participants felt they had learned most about sleep promotion through clinical experience, from staff, patients and their own life experiences rather than their educational programmes. Their learning was unstructured, learning by being in practice as opposed to reflecting on practice and they lacked declarative knowledge about sleep and its promotion. The participants held generally positive attitudes to sleep but for some there were clear blocks to their practice, including the attitudes of others, ward culture and routine orientation of care, resulting in sleep promotion having a low priority. A model of sleep promotion practice and a characterisation of sleep promoting behaviour were developed from the participants' descriptions and experiences. Conclusions. These findings highlighted the need to address the acquisition of knowledge and skills on sleep and its promotion. A new framework is proposed for this purpose. The clinical implications include the need to increase awareness of all staff, particularly through managers who have responsibility for encouraging positive attitudes towards sleep promotion.