Objective: Caregivers experience physical and mental stress that ends up lowering their quality of life (QoL). Our goal was to research (a) the level of caregivers QoL; (b) the relationships between the demographic characteristics of the caregivers, their caregiving burden, their family functioning, their social and professional support and their QoL and (c) the best predictors of caregivers QoL. Methods:100 key caregivers (70% parents, 8% spouses, 17% siblings and 5% children) were studied using the world health organization quality of life-Bref (WHOQOL-BREF) to research their QoL, the Zarit Scale to assess their perception of their caregiving burden, the Social Network Questionnaire to examine their social support, the Family APGAR to assess the satisfaction with social support from the family and a professional support scale (Escala de Apoyo Profesional) to determine the professional support received by caregivers was performed. Results: Scores on the WHOQOL-BREF in the Physical, Psychological, Social and Environment domains were 15.0 (SD = 3.7), 13.3 (SD = 4.2), 11.0 (SD = 4.7) and 13.5 (SD = 3.1), respectively. Through bivariate analysis, the dimensions that showed a positive significant association with QoL were being a young male caregiver who was a working father with a high educational level and help from other family members. Caregivers of patients who were older and had a later onset of the illness, a lower score on the Zarit Scale and a high score on the Social Network Questionnaire, Family APGAR and Escala de Apoyo Profesional showed higher QoL. Many of these variables made a unique contribution in the multivariate analysis. Conclusions: There is a significant association between the caregiver’s burden and their QoL. Regression analysis showed that the best predictors of QoL were caregiving burden, social support and professional support.