BACKGROUND: Men living with heart failure (HF) in middle-age experience restrictions limiting their work capacity and/or social activities. To adjust to the life-situation they need support. The meaning of the phenomenon of support is not well known. Thus, formal carers may find it problematic to know how to support patients. AIM: The aim of the current study was to uncover and describe the meaning of the phenomenon of support as experienced by men living with HF in middle age. DESIGN: The study used a caring science perspective and a reflective lifeworld approach based on phenomenological philosophy. PARTICIPANTS AND SETTINGS: Nine men, aged 49-64 years and diagnosed with HF, were recruited from two outpatient HF clinics in Sweden. METHODS: Interviews were used for data gathering. Data were analyzed by means of reflective lifeworld research. FINDINGS: The essence of support as experienced by men living with HF in middle age can be understood as security, and a sense of having control over body and situation. Support is realized in the men's relations to other people; there is however tension between what is supportive and what is not, meaning that even though intentions are good, intended support involves limitations, uncertainties or insecurity. The essence is illuminated by the following meaning constitutes: Support-a tenuous security; Medications-a support for life; Conditional support within the context of formal care; and, Information and knowledge. CONCLUSIONS: The meaning of support as experienced by men living with HF in middle age is multi-dimensional, qualitative and contextual. When the men are supported they gain a sense of security and control, giving them strength to handle their life-situation. A lifeworld-led approach in the context of formal care can help formal carers support men living with HF in middle age.