Objective: to compare the life satisfaction of family caregivers, taking into account their gender, age, time since starting care, health, religion, perceived burden and quality of life, and the level of physical and cognitive dependence of the elderly person receiving care, and to investigate the associations between these variables and low life satisfaction. Methods: a total of 148 caregivers in Indaiatuba and Campinas, in the state of São Paulo, Brazil, selected using the convenience method, were interviewed at home, in private medical clinics and outpatient units, using questionnaires about the sociodemographic characteristics, health conditions, time since starting care, scales of life satisfaction, religiosity, perceived burden and quality of life of the caregiver, and the physical and mental health of the elderly person receiving care. Descriptive, Multivariate and Univariate Logistic Regression analysis were used. Results: caregivers who exhibited low life satisfaction included more frail individuals, with three or more chronic diseases and depression, greater perceived burden and lower self-fulfillment and pleasure, and control and autonomy, scores, which are factors of the Perceived Quality of Life Scale. Elderly caregivers who scored low in self-fulfillment factor and pleasure (OR=101.29;) and who scored high in perceived burden (OR=5.89, CI=2.13 to 16.24) had a greater chance of having low life satisfaction scores. Conclusions: The assessment of caregivers of their satisfaction with life is more influenced by subjective than objective variables, and low satisfaction seems to be strongly associated with poor quality of life, high burden, and caregiver frailty.