Background: Unclear illness perceptions are common in heart failure. The self-regulation model of illness behaviour highlights factors that may impact how people with chronic illness choose to cope with or manage their condition and has been used to study pre-hospital delay for stroke and acute myocardial infarction. The principles of self-regulation can be applied in heart failure to help illuminate the link between unclear illness perceptions and sub-optimal symptom self-management. Objective: Informed by the self-regulation model of illness behaviour, this study examines the role of illness perceptions in coping responses that lead to delayed care-seeking for heart failure symptoms. Design: Mixed-methods phenomenological study. Setting(s): Quaternary referral hospital - centre of excellence for cardiovascular care and heart transplantation. Participants: Seventy-two symptomatic patients with heart failure participated in a survey assessing illness perceptions. A subset of fifteen individuals was invited to participate in semi-structured interviews. Methods: Illness perceptions were assessed using the Brief Illness Perception Questionnaire. In-depth semi-structured interviews were conducted to elicit previous care-seeking experiences and decision-making that led to a passive, or active coping response to worsening symptoms. Descriptive statistics were used to report questionnaire findings, and open-ended responses were grouped into descriptive categories. Interpretative phenomenological analysis was undertaken on interview transcripts. Results: Participants perceived little personal control over their condition and mostly attributed heart failure to lifestyle factors such as diet and lack of activity. Cognitive dissonance between perceived self-identity and heart failure-identity led to a highly emotional response which drove coping towards avoidance strategies and denial. Conclusions: This study demonstrates the use of the principles of self-regulation in heart failure and offers a framework to understand how patient representations and emotional responses can inform behaviour in illness. Findings highlight the value of empowering patients to take control of their health and the need to help align values (e.g. independence) with behaviours (e.g. actively addressing problems) to facilitate optimal symptom self-management.