ObjectiveTo measure the experience of the person having a rare disease in order to identify objectives for optimal care in the health care received by these patients. Methods. A cross-sectional study was conducted in Spain involving patients associated with the Spanish Rare Diseases Federation [Federación Española de Enfermedades Raras] (FEDER). A modified version of the PREM IEXPAC [Instrumento para evaluar la Experiencia del Paciente Crónico] instrument was used (IEXPAC-rare-diseases). Scores ranged between 0 (worst experience) and 10 (best experience).ResultsA total of 261 caregivers (in the case of paediatric population) and patients with rare diseases (response rate 54.4%) replied. 232 (88.9%) were adult patients and 29 (11.1%) caregivers of minor patients. Most males, 227 (87%), with an average age of 38 (SD 13.6) years. The mean time since confirmation of diagnosis was 7.8 (SD 8.0) years. The score in this PREM was 3.5 points out to 10 (95%CI 3.2–3.8, SD 2.0). Caregivers of paediatric patients scored higher, except for coordination of social and healthcare services.ConclusionsThere are wide and important areas for improvement in the care of patients with rare diseases. This study involves a first assesment of the experience of patients with rare diseases in Spain.