Aims The aims of this study were (i) to evaluate the effects of using an m-health tool on self-care behaviour at 3 and 12 months and (ii) to explore the experiences and perceptions of heart failure (HF) patients about the m-health tool.Methods and results In this pre-post interventional study with a mixed-method analysis, 71 patients diagnosed with HF [49% female, mean age 76.7 years, New York Heart Association (NYHA) II 31%, NYHA III 69%] were enrolled and had the m-health tool installed in their home for 1 year. The tool consisted of a pre-programmed tablet including a weighing scale and interactive education about HF self-care. At baseline, and at 3 and 12 months, self-care was assessed using the European Heart Failure Self-care Behaviour (EHFScB-9) Scale, an eight-item self-administered questionnaire assessing the experiences of the m-health tool. The mean EHFScB-9 at baseline was 63.8 +/- 2.8 and it improved to 67.6 +/- 7.6 after 3 months (P < 0.05). After 1 year, the score had decreased to 63.2 +/- 7.1 (P = 0.68). Most patients rated the tool as 'good', both at 3 months (92%) and after 12 months (93%). Some found the system to be unnecessary to some degree, and this number increased between 3 and 12 months (P < 0.001). Most patients felt that m-health increased their feelings of security, and 85% responded that the system increased their family members' sense of security.Conclusion The m-health tool significantly improved patients' self-care behaviour after 3 months, but this effect did not persist after 1 year. For achieving long-term effects and outcomes, additional and regularly updated self-care support may be needed.