Aims The recent rise in the number of nonagenarians (age >= 90 years) undergoing percutaneous coronary intervention (PCI) has revealed gaps in research, in particular on patients' experiences. Therefore, the aim of the study was to explore and describe nonagenarians' internal resources and their experiences of the in-hospital pathway.Methods and results Nineteen nonagenarian patients (women n = 9), mean age 91 years, 9 acutely, and 10 electively treated, were consecutively enrolled from a tertiary university hospital from June 2021 to February 2023. In-depth interviews were conducted during hospitalization, audiotaped and transcribed. The interviews were analysed using qualitative content analysis. Three sub-themes emerged from the nonagenarians' experiences with the PCI treatment trajectory: (i) Taking lifelong responsibility for own physical and mental health describes a population striving to live a healthy life and to stay independent. Physical and mental activities including healthy food choices had been an integral aspect of their lives from early childhood. (ii) Individual internal resources influenced the PCI pathway describes how their internal resources were used, from actively engaging in the decision-making process to withstanding discomfort during the PCI procedure. (iii) The post-PCI pathway was multifaceted describes a short stay at the cardiac ward with individual post-procedural experiences, close monitoring, and preparation for discharge including cardiac rehabilitation.Conclusion Nonagenarians undergoing PCI demonstrated a personal incentive to stay healthy and independent. Their internal resources of independence, stoicism, and resilience were used during their in-hospital stay contributing to a successful PCI procedure. Individual cardiac rehabilitation strategies were highlighted after discharge from hospital. Graphical Abstract