Aim: The aim of the study was to investigate the degree of adherence and non-adherence to treatment regimen in the population with heart failure, as well as to explore relationships to symptom burden and hospitalization-frequency. Introduction: Heart failure – a chronic disease with a somber prognosis and high mortality, incidence and prevalence increasing world-wide. Adherence to treatment regimen mitigates symptom flare-up, increases life quality and impedes hospitalizations. Non-adherence is a global problem, historically underestimated and difficult to measure. The level of non-adherence to medical treatment in the heart failure-population is about 50 %, degree of non-adherence from a wider perspective implicates a gap of knowledge. Methods: A cross-sectional survey-study was conducted via the electronic survey: ”Living with heart failure”. Selection was consecutive, based on patients visiting the Cardiac outpatient-clinic, in a Swedish University Hospital. Data was transferred to descriptive statistics using the statistical processing program SPSS. Results: 479 individuals participated, non-adherent were 73,6 % and adherent 26,4 %. There was a significant difference between symptom burden among the non-adherent and the adherent. A trend also appeared between low hospitalization-frequency, high degree of adherence and low symptom burden, an equivalent trend among the most frequently hospitalized which exhibited the lowest degree of adherence and the most severe symptom burden. Conclusion: The results pinpoint the need to further draw attention to non-adherence, repeatedly representing the majority of the population. With a patient-centered approach nurses/caregivers could have an empowering effect on the patient´s ability to health literacy and thus promote conditions for adherence.