Aim and objectives:The aim of this study was to develop a theory to help guide patients with end-stage renal disease to adapt to peritoneal dialysis.Background: Taiwan ranks first worldwide in end-stage renal disease incidence and dialysis prevalence. Many patients cannot accept long-term dialysis treatment and thus face several physical and psychological suffering. No theory has yet been developed to help guide patients with end-stage renal disease to adapt to peritoneal dialysis.Design: A grounded theory approach was used in this study. Methods:A theoretical sampling was performed after interviewing 25 patients who had adapted to peritoneal dialysis at a medical centre in Taiwan from January 2018 to September 2018; data saturation was achieved. Data were analysed using open, axial and selective coding and while using the constant comparison technique. COREQ reporting guidelines were utilised.Results: A substantive theory was developed to help guide patients with end-stage renal disease to adapt to peritoneal dialysis. The core category that emerged from the data collected was 'Confronting peritoneal dialysis to live and co-exist with peritoneal dialysis'. Other key categories linked to and embraced in this core category were as follows: positive self-regulation, regulation of daily life and the process of adaptation to dialysis method. Conclusion:The results could help healthcare professionals to better understand the process of end-stage renal disease patients' adaptation to peritoneal dialysis, thereby facilitating patients' adaptation to dialysis in their daily life, enhancing their quality of life and improving the quality of medical care.Relevance to clinical practice: Healthcare professionals could use this theory as reference when providing care for peritoneal dialysis patients to assist them in adapting to life with peritoneal dialysis as soon as possible through positive self-regulation, daily life adjustments and the process of adapting to the dialysis method.