The study explored beliefs about health and illness in Latin American migrants diagnosed with diabetes mellitus (DM) living in Sweden, and investigated the influence on health-related behavior including self-care and care-seeking behavior. Migrants are particularly affected in the diabetes pandemia. Beliefs about health and illness determine health-related behaviour and health but no studies have been found on Latin American migrants with DM. An explorative study design with focus-group interviews of nine persons aged 36-77 years from a diabetes clinic was used. Health was described from a pathogenetic or a salutogenetic perspective: 'freedom from disease or feeling of well-being', and being autonomous and able to work. Economic hardship due to expenses for medications and food for DM affected health. Individual factors such as diet, exercise and compliance with advice, and social factors with good social relations and avoidance of stress, often caused by having experienced severe events related to migrational experiences, were considered important for maintaining health and could cause DM. Disturbed relations to others (social factors), punishment by God or Fate (supernatural factors), intake of diuretics and imbalance between warmth and cold (natural factors) were also perceived as causes. A mix of biomedical and traditional explanations and active self-care behaviour with frequent use of herbs was found. It is important to assess the individual's beliefs, and health professionals, particularly nurses, should incorporate discussions of alternative treatments and other components of explanatory models and co-operate with social workers to consider influence of finances and migrational experiences on health.