BackgroundSeveral heart failure studies have shown promising results for implementing telehealthcare. These studies have led to clinical and political interest in telehealthcare as a way to improve heart failure outcomes and lower costs. However, there is a need for large-scale clinical trials with cost-effectiveness assessments.Methods/designThe present study is known as the TeleCare North Heart Failure Trial in Denmark. We are studying the health effectiveness and cost-effectiveness of a telehealth (Telekit) solution compared with usual care for patients with heart failure. The design is a multicenter, two-arm, parallel-group, nonblinded, superiority randomized controlled trial. Outpatient healthcare centers will be responsible for recruiting eligible participants (600 participants are expected) for the trial in the geographic area of the North Denmark Region. Participants are qualified for inclusion if they have been diagnosed according to national guidelines and are categorized in New York Heart Association class 2, 3, or 4. Patients must have a permanent residence and be motivated to use telehealth care. The primary outcomes are changes in health-related quality of life (assessed using the Kansas City Cardiomyopathy Questionnaire, the EuroQol EQ-5D-5L questionnaire, and the Short Form Health Survey [SF-36]) and in the incremental cost-effectiveness ratio measured from baseline to follow-up. The secondary outcomes are changes in mortality and in physiological indicators such as blood pressure, pulse, and weight.DiscussionThe TeleCare North Heart Failure Trial is intended to improve the international evidence base for the health effectiveness and cost-effectiveness of telehealthcare for patients with heart failure. The expectation is that the results of the trial can be generalized to all municipalities in Denmark and serve as an inspiration for further international research.Trial registrationClinicalTrials.gov (NCT02860013). Registered on 28 July 2016.Electronic supplementary materialThe online version of this article (doi:10.1186/s13063-016-1722-5) contains supplementary material, which is available to authorized users.