Background: Alzheimer is a pathology that concers the patient and his family having a physical, social, economic and psychological impact. Research on family caregivers is still lacking and little is known about caregivers burden and ist associated factors in Tunisia. Objectives: The aim of this study were to describe caregiver burden among Tunisian family caregivers of patients with alzheimeŕs disease, its associated factors and ist relationship to social support. Methods: We conducted a cross-sectional study among 118 family caregivers during three months at the neurology outpatient departments of two university hospitals. Sahloul, Sousse and Taher Sfar, Mahdia. Using the Zarit Burden Interview-22 (ZBI)items and the Medical Outcome Study-Social Support Survey to assess burden and social support among the caregivers. Results: We included 118 caregivers of patients with Alzheimeŕs disease,with an average age of 45±15 years. Women were more predominant with a sex ratio of 0.57.Half of caregivers were the descent of patients. The Mean years of caregiving was 5±3 years with an average of 13 hours ±3 of care assistance per day. The mean ZBI Score was 38.4±18.5 and 16.1% of caregivers percived a severe burden. The mean ZBI Score was higher in female, retired, lowmsocio economic status and in rural area with a statistically significance difference. We found that caregiver burden and social support were highly correlated (p < 0.001,r=-0.41)indicating that a high level of caregiver burden was asoociated with a less level of social support. Conclusions: The level of burden in family caregivers who are caring for a patient with alzheimeŕs disease is high. A considerate help and support from helth care and social institutions is required by taking into account the factors that contribute to caregivers burden and considering the importance of social support in alleviating caregiver burden. Key messages: The level of burden in family caregivers who are caring for a patient with alzheimeŕs disease is high. High level of caregiver burden was asoociated with a less level of social support.