Background: Surgical care increasingly shifts pre- and postoperative care responsibility to patient self-care at home. By using the capability, opportunity, motivation-behaviour (COM-B) framework, patient determinants influencing self-care can be explained.Aim: The aim was to describe patients' experienced facilitators of and barriers to self-care in surgical fast-track programmes related to capability, opportunity and motivation.Methods: A qualitative design study with semi-structured interviews was conducted among 27 general and orthopaedic surgery patients at three Swedish hospitals. Data were analysed deductively using the COM-B framework.Results: The patients' self-care experiences were explained by capability, opportunity and motivation and the dynamic interaction between these factors. A key analytical finding was the pivotal role of family and friends, whose emotional and practical support strengthened patients' capability and motivation. Facilitators for behaviour change included prior surgical experience, clear information, physical ability, social and professional support, optimism and realistic goals. Barriers included cognitive and physical limitations, pain, fatigue and emotional distress.Conclusions: Findings highlight family involvement as an underused resource and support policy development of person centred pre- and postoperative self-care strategies. This study advances nursing theory by applying the COM-B model to illuminate interdependent behavioural processes in surgical self-care; themes could occasionally overlap.