Background. Self-care refers to behaviors that individuals adopt to prevent or maintain the stability of an illness (self-care maintenance), to monitor signs and symptoms (self-care monitoring), and to respond to signs and symptoms of an illness exacerbation (self-care management). A generic measure of self-care, the Self-Care of Chronic Illness Inventory, based on the Theory of Self-Care of Chronic Illness, was developed for use in individuals with any number and type of chronic conditions.Objective. The current study investigated the measurement equivalence of the Self-Care of Chronic Illness Inventory in individuals from three different cultural groups. We were interested in determining if Italians, Swedes, and Americans interpret the measure in a conceptually similar way. Methods. This cross-sectional study enrolled 1,629 patients, 784 recruited in Italy, 438 in Sweden and 407 in the United States. Self-care (self-care maintenance, self-care monitoring and self-care management) was measured with the Self-Care of Chronic Illness Inventory. A multi-group confirmatory factor analytic approach was used to assess the equivalence of the measures across the three countries. Configural, metric, scalar and strict invariance were tested through a series of nested models where increasingly stringent equality constraints were posited.Results. Participants were mostly males (54.3%), older adults (68.9%) and had at least two chronic conditions. Results indicated that three out of four measurement equivalence levels were partially or totally supported in all three of the Self-Care of Chronic Illness Inventory scales. The partial scalar invariance level was reached for self-care maintenance [χ 2 (50) = 63.