Newly graduated nurses and those experienced nurses who enter a new workplace need preceptors for being orientation to an unfamiliar work environment. The aim of this study was to explore the lived experiences of newly nurses’ preceptors of preceptorship. This study was conducted using an interpretive phenomenological design based on the Heidegger’s philosophical thoughts. Participants were consisted of six preceptors of newly nurses working in a teaching hospital in an urban area in the northwest of Iran. They were chosen using a purposive sampling method. In-depth interviews were held from July 2014 to March 2015 and collected data were analysed using the Diekelmann et al.’s method. The data analysis led to the development of two key themes. The first one was ‘professional commitment’ with the subthemes of ‘generous sharing of unique treasure of knowledge and professional experiences’, ‘internal motivation’, and ‘beyond preceptorship’. The second theme was‘ preceptorship as an opportunity for growth’ with the sub-themes of ‘preceptor’s personal and professional growth’, ‘mutual learning’, ‘facilitating the professional growth of newly nurses’ and ‘holistic benefits’. Having spiritual motivations in the favour of playing the preceptor role and preceptorship as holistic benefits were new findings that were developed in this study. The need for skilful and committed preceptors in nursing education and practice will never ended. Nurse managers are required to support preceptors and motivate them to take the preceptor role in healthcare settings. Also, they need to preserve the connection between newly nurses and preceptors through putting them in the same work shift at the end of the preceptorship programme. There is a need to use the preceptorship programme for developing a positive atmosphere in healthcare settings to increase the overall quality of hospitals.