Introduction: Symptom perception in heart failure (HF) has been identified as crucial for effective self-care, and is related to patient and health system outcomes. There is uncertainty regarding the feasibility and acceptability of symptom perception support and doubts regarding how to include informal caregivers. This study aims to test the feasibility, acceptability and outcome responsiveness of an intervention supporting symptom perception in persons with HF and their informal caregiver. Methods and analysis: A feasibility study with a quasi-experimental pretest and post-test single group design is conducted. The convenience sample consists of 30 persons with HF, their informal caregivers and six nurses. SYMPERHEART is an evidence-informed intervention that targets symptom perception by educational and support components. Feasibility is measured by time-to-recruit; time-to-deliver; eligibility rate; intervention delivery fidelity rate. Acceptability is measured by rate of consent, retention rate, treatment acceptability and the engagement in the intervention components. Outcome responsiveness includes: HF self-care (via the Self-care of Heart Failure Index V.7.2); perception of HF symptom burden (via the Heart Failure Somatic Perception Scale V.3); health status (via the Kansas City Cardiomyopathy Questionnaire-12); caregivers’ contribution to HF self-care (via the Caregiver Contribution to Self-Care of Heart Failure Index 2); caregivers’ burden (via the Zarit Burden Interview). Clinical outcomes include HF events, hospitalisation reason and length of hospital stay. Descriptive statistics will be used to report feasibility, acceptability, patient-reported outcomes (PRO) and clinical outcomes. PRO and caregiver-reported outcome responsiveness will be reported with mean absolute change and effect sizes. Ethics and dissemination: The study is conducted according to the Declaration of Helsinki. The Human Research Ethics Committee of the Canton of Vaud, Switzerland, has approved the study. Written informed consent from persons with HF and informal caregivers are obtained. Results will be published via peer reviewed and professional journals, and further disseminated via congresses. Trial registration number: ISRCTN18151041.