Objectives: To clarify how the care burden of primary family caregivers is associated with social cohesion in an urban area of Tokyo, Japan.Study designCross‐sectional study. Methods: A questionnaire survey of primary family caregivers was conducted in Tokyo in 2015. Social cohesion was examined using the social capital indicators of Kondo et al, and the care burden of primary family caregivers was assessed by the Zarit Care Burden Interview Scale in Japanese short version (J‐ZBI_8). Data were analyzed by multiple regression models.