Throughout the world, life expectancy has noticeably increased during the past decade, and health promotive initiatives for older persons will therefore become ever more important. During the past few years, interest in what constitutes the source of health for human beings has markedly increased in health science research. An interesting and relatively unresearched domain is what provides older persons the strength and energy to look forward and what positively or negatively influences older persons' vitality. The aim of the study was to explore and describe older persons' vitality and their subjective experiences of what influences their vitality, despite disease and suffering. The study has an explorative and descriptive design. A comprehensive questionnaire including two open-ended questions about vitality was sent to 4927 older persons aged 65 and 75, and a total of 2579 responded to the open-ended questions. Qualitative content analyses were used. A safe and confirming communion, meaningful activities, an optimal state of health and an inner strength were important sources of vitality. Ageing that includes illness or a restricted life, happenings in the world and in one's close environment that threaten inner meaningfulness, and mental burdens that give rise to a feeling of hopelessness or depression decrease vitality. Vitality is an important health resource for 65- and 75-year-olds in that it influences a person's longing for life, love and meaning. Accordingly, it is of fundamental importance that Registered Nurses and other healthcare personnel strengthen older persons' vitality during the ageing process. By taking into consideration that which positively vs. negatively affects the vitality of each unique person, healthcare personnel can strengthen each older person's health resources and attempt to minimise and limit what negatively influences said person's vitality.