Aim: To describe why young registered nurses (RNs) had previously left an organisation and why they intend to leave the profession. Background: Currently, many young registered nurses, including those in Finland, are considering leaving their job or have an intention to leave the profession. Design: An in-depth, descriptive approach was adopted. Method: Data were collected in 2012 from interviews with 15 registered nurses (under the age of 30 years). The interviews were semi-structured and analysed using conventional content analysis. The main questions addressed were: 'Why had the young registered nurses left their previous organisation?' and 'Why do young registered nurses have an intention to leave the profession?' Results: The findings centre on three themes: poor nursing practice environments; lack of support, orientation and mentoring, and nursing as a 'second best' or serendipitous career choice. Conclusions: The first years of nursing are particularly stressful for newly-graduated and inexperienced registered nurses. An in-depth, qualitative approach reveals more complex reasons behind the turnover of registered nurses and intention to leave the profession than questionnaire surveys. Implications for nursing management: Young registered nurses need social support from nurse managers and experienced colleagues to successfully transition into nursing practice environments. Adequate orientation and mentoring programmes are needed to facilitate this transition. © 2014 John Wiley & Sons Ltd.