In patients with heart failure (HF), self‐care, and caregiver contribution to self‐care (i.e., the daily management of the disease by patients and caregivers) are essential for improving patient outcomes. However, patients and caregivers are often inadequate in their self‐care and contribution to self‐care, respectively, and struggle to perform related tasks. Face‐to‐face motivational interviewing (MI) effectively improves self‐care and caregiver contribution to self‐care, but the evidence on remote MI is scarce and inconclusive. The aims of this randomized controlled trial will be to evaluate whether remote MI performed via video call in patients with HF: (1) is effective at improving self‐care maintenance in patients (primary outcome); (2) is effective for the following secondary outcomes: (a) for patients: self‐care management, self‐care monitoring, and self‐efficacy; HF symptoms; generic and disease‐specific quality of life; anxiety and depression; use of healthcare services; and mortality; and (b) for caregivers: contribution to self‐care, self‐efficacy, and preparedness. We will conduct a two‐arm randomized controlled trial. We will enroll and randomize 432 dyads (patients and their informal caregivers) in Arm 1, in which patients and caregivers will receive MI or, in Arm 2, standard care. MI will be delivered seven times over 12 months. Outcomes will be assessed at baseline and 3 (primary outcome), 6, 9, and 12 months from enrollment. This trial will demonstrate whether an inexpensive and easily deliverable intervention can improve important HF outcomes. With the restrictions on in‐person healthcare professional interventions imposed by the COVID‐19 pandemic, it is essential to evaluate whether MI is also effective remotely.