ABSTRACT Background There is growing evidence that antenatal education incorporating relaxation practices can positively influence perinatal psychological wellbeing. However, a paucity of qualitative research is evident. Gaining insight into how and why such education may influence childbearing women, can inform the design of effective educational interventions. This study aimed to explore the perspectives of women and their partners on how and why a single Antenatal Relaxation Class (ARC) might influence perinatal psychological wellbeing and childbirth experiences. Method In this descriptive qualitative study, 17 women and 9 partners participated in semi-structured in-depth interviews and the data were analysed using thematic analysis. The study was carried out in a Scottish NHS Health Board where ARC was provided to expectant parents. Findings Two themes were generated, namely: ‘the turning point’, and ‘recognition of an inner resource’. Participants perceived ARC as ‘the turning point’ when they became more confident, equipped, and less fearful and anxious towards childbirth. ‘Understanding of the psychophysiological processes of childbirth’, ‘positive stories’, and ‘practice of relaxation techniques’ were reported as the main reasons for these positive changes. Participants explained ARC had enabled them to access a deep sense of calmness as ‘an inner resource’ and motivated the use of relaxation techniques as a self-care behaviour throughout pregnancy and childbirth. Conclusion A single antenatal relaxation class has the potential to enhance perinatal psychological wellbeing and childbirth experiences. This study provides valuable insights for maternity services seeking to develop effective health-promoting antenatal education.