Background: Stress in the nursing workplace has significant consequences for both the person and the organisation, such as psychological and physical health deterioration, financial and social impact, and impaired professional practice. This study sought to measure and compare the perceived levels of job–related stress and stressors of newly qualified nurses and fourth-year student nurses in the clinical environment and to explore the participants’ views on stress and stressors from a qualitative perspective. Methods: This study used a cross sectional survey design, using self-reporting questionnaires to measure and compare levels of stress in both groups in one region of Ireland. The instrument used was ‘The Nursing Stress Scale’, complemented by an open-ended question, which was analysed qualitatively. Data were obtained from newly qualified nurses (n=31) and fourth year student nurses (n=40) in six acute hospital sites. Findings: Levels of stress were high in both groups. Perceived stress was not higher in newly qualified nurses compared to fourth-year student nurses for the following factors: death and dying, inadequate preparation, lack of staff support, uncertainty concerning treatment and conflict with other nurses. However, perceived stress in relation to workload and conflict with physicians was higher in newly qualified nurses compared to fourth-year student nurses. Themes identified from the responses to the open question by both groups included excessive workload, relationships with other nurses and lack of support. Newly qualified nurses also referred to lack of preparation and confidence in new role, moving wards and made suggestions for improvement. Some student nurses felt excluded, had difficulties combining academic demands with clinical placement and reported unmet learning needs. Implications: These results can help stakeholders in nurse education and practice to develop interventions to reduce stress for both groups and to ease the transition from student to graduate nurse, thereby helping to retain this valuable human resource within nursing.