Aims: The aim of this study was to investigate social support in relation to self-rated health and the prevalence of low mood in people on sick leave due to heart failure. Methods: A cross-sectional design was used, and 590 individuals on sick leave due to heart failure in Sweden responded to the postal questionnaire. The questions therein concerned received and needed functional and structural support from managers, work colleagues, families and friends. Multivariate analyses were conducted. Results: The variables of income and needed support from family contributed significantly and negatively to self-rated health. Those who perceived that they needed more support from their manager reported experiencing low mood more frequently. Conclusions: The results showed a negative relation between manager support and low mood. Thus, support from managers and perceptions of low mood during sick leave are negatively associated, however, we do not know anything about the causality of this association. The results also indicated that needed support from family was negatively associated with self-rated health. The results also highlighted a multidimensional frailty in people with heart failure that needs to be recognized in future research as well as in clinical practice.