AIM: To describe the perceptions held by Iranian registered nurses (IRNs) concerning their night shift work experiences. BACKGROUND: Due to the nature of nursing work and the need for 24-h coverage every day, the majority of nurses work night shifts in their professional practice. Evidence from several studies indicates that night working is a challenge for most nurses. This situation can cause many forms of physical and emotional stress. METHODS: A qualitative design was used with purposeful sampling. Eighteen IRNs from four different general educational hospitals in Iran took part in the study. Data were collected via semi-structured interviews and analysed according to qualitative content analysis. FINDINGS: Three main themes were identified from the data: (a) socio-cultural impacts of night work, (b) health-related impacts of night work, and (c) night work as an opportunity for gaining more clinical experiences and learning more. CONCLUSION: The impact of shift work on nurses' daily professional behaviour and adverse health outcomes related to shift work should be well understood and considered when organizing healthcare systems. We need to identify ways to support nurses who work nights and also give attention to the caregiver's needs.