The present study was designed to test the hypothesis that there is an independent association between the three concepts of psychosocial factors, social network, social support, social influence and blood pressure (see Materials and methods for definition). The study sample chosen (n = 621) comprised a randomly selected group of half the male residents of Malmö born in 1914, 500 (80.5%) of whom participated. A study based on a model with clearly defined criteria was used to measure the different aspects of social network, social support and social influence. In multiple regression analysis, social anchorage (a subconcept of social network) was shown to have an association with both systolic (P = 0.03) and diastolic blood pressure (P less than 0.001), when adjustments for social class, marital status, medication for hypertension, alcohol consumption, smoking habits, body mass index (BMI) and physical activity were made. Social anchorage is a concept on a structural level, that describes to what degree the individual belongs to and is anchored within formal and informal groups in society. As such, it may contribute to a deeper understanding of mechanisms behind high blood pressure and could thus be significant in the field of health promotion.