Abstract Background Rett syndrome is a rare neurodevelopmental disorder associated with functional impairments that emerge in early childhood and persist throughout life. Despite improved understanding of its genetic basis and natural history, therapeutic options remain limited, and care frameworks across Europe are highly variable. This study aimed to characterize the lived experiences, unmet needs, and evolving challenges faced by individuals with Rett syndrome and their caregivers across multiple European countries. Results Sixty caregivers across eight countries completed five-day diaries, and thirty participated in in-depth interviews. The sample represented children (36%), adolescents (42%), and adults (22%) with Rett syndrome; 97% were female. Difficulty using hands (reported by 88% of caregivers) and difficulty communicating (78%) were the most frequently observed symptoms. Daily activities were heavily affected, with symptoms impacting 59% of activities for children, 61% for adolescents, and 38% for adults. Some comorbidities increased with age, including scoliosis (45% in children vs. 92% in adults) and pneumonia (54% in adults). Care demands were substantial, with caregivers of adults spending an average of 41 hours per week providing emotional support alone, along with high time requirements for feeding (20 hours), washing and bathing (8 hours), and administering medication (5 hours). Conclusions Caregiver experiences across Europe reveal a consistent pattern of unmet needs, high symptom burden, and fragmented, poorly coordinated care for individuals with Rett syndrome. The changing needs across the lifespan underscore the importance of anticipatory, multidisciplinary care models and improved transition pathways into adulthood. As participants were recruited through patient advocacy groups, the study population may represent a comparatively informed and healthcare-engaged subgroup of caregivers, highlighting that unmet needs and care challenges across the broader RTT caregiver community may be even greater among families with less access to advocacy networks and specialized support resources. These findings highlight the need for system-level changes and the development of comprehensive, standardized care frameworks for Rett syndrome across Europe.