Background: To support and strengthen parenting skills, it is mandatory for municipalities in Sweden to offer parental education programmes to all parents. One such programme is the "Circle of Security-Parenting" (COS-P), in which parents participate in eight weekly group sessions, each lasting 90 minutes. COS-P helps parents recognise and respond to their child's emotional needs for attachment. The programme focuses on enhancing parents' understanding of their child's behaviour, enabling them to address emotional needs effectively and foster security to benefit the child's overall development. Objective: This study aimed to explore parents' experiences of participating in COS-P parental education programme from a health-promotive perspective. Design: Qualitative design using an inductive approach. Setting: The COS-P programme was conducted in a medium-sized town in Sweden. Method: Nineteen semi-structured interviews were conducted and analysed using qualitative content analysis. Results: The analysis of the data resulted in one latent theme: from uncertainty and chaos to consciously empowering qualities; and five categories with it -- parents' understanding of the child needs developed; parents learned to handle conflicts and set boundaries; parents' ability to reflect increased; parents' inner security and calmness was strengthened; and parents' stress was reduced. Conclusion: The findings show that the COS-P is a relevant programme for municipal authorities to offer parents as the result point at the programme's ability to empower parenting and strengthen the attachment between parent and child. The programme contributed to increased self-efficacy, well-being and confidence in parenting and could therefore be seen as a useful health promotion intervention.