Given the rate of the undiagnosed cases of dementia and the consequences of inappropriate care, understanding the factors that explain the use of medical and health care in dementia is a critical concern. Our objective was to identify the psychosocial and medical determinants of use of care in dementia. The study sample consisted of 308 participants: the persons with dementia (n = 99) selected from three French population-based cohorts (i.e. PAQUID, 3C, AMI), their family caregivers (primary, n = 96, and secondary, n = 51), and their general practitioners (n = 62). Use of care in dementia was considered according to two indicators: (1) recourse to secondary care, (2) number of community and health services used. Multiple logistic models including sociodemographics and psychosocial variables revealed that the determinants of nonuse of care are similar both for the recourse to secondary care and for the number of community and health services used: lack of education and the contribution of the people with dementia to the decisions regarding their own care and dementia care services in the community area. In addition, satisfaction of the primary caregiver with the services used by his/her relative is associated with non-recourse to secondary care. Taken together, these results highlight the predominant role of psychosocial factors in the use of care in dementia and the importance of addressing this issue through an integrative approach including psychological, social, medical, and family dimensions.< Réduire