OBJECTIVES: To assess the nature and extent of burden experienced by caregivers of patients with Fragile X Syndrome (FXS) in the United States (US). METHODS: A total of 351 caregivers enrolled in a FXS survey research registry completed a web-based (93%) or phone-based (7%) survey that captured information on health care utilization, financial burden, employment status, paid and unpaid caregiver hours, and caregiver injuries and mental health. RESULTS: Respondents (293 with male child; 58 with female) were mostly female (91%), Caucasian (92%), and married (84%) with an average age of 50 years. Caregivers reported low hospitalization rates (2%) and Emergency Department visits (6%) over the past 12 months. The most commonly seen specialists were ophthalmologists (33%), psychiatrists (33%), developmental-behavioral pediatricians (28%), and neurologists (22%). 40% of males and 22% of females needed at least one of 11 common medical tests/ procedures (e.g. CT scan, X-Ray). Nearly 19% of patients needed general anesthesia/ sedation for a dental procedure. 66% were on at least one prescription medication for problems related to FXS. On average, parents spent nearly 9 hours/ day caring for their child. They also obtained 5 hours of paid support/ day. During the past 30 days, the average caregiver and their spouse took 19 hours off from work to care for their child. More than 35% reported that someone in their family had quit working, 28% turned down a job or promotion, 54% changed work hours, and 26% changed jobs.  Nearly 29% reported being injured by their child with FXS (16 injuries per year by male children; 4 injuries per year by female children). 35% of caregivers reported seeking treatment for depression or anxiety, and 28% took prescription medications to treat these symptoms. CONCLUSIONS: Caring for a child with FXS is associated with substantial caregiver burden and increased health care utilization.