Background: Rare Anaemia Disorders (RAD) include a highly heterogeneous group of rare and ultra-rare haematological conditions. The numbers of RAD patients included in clinical research are rarely adequate in one centre or even country. However, the lack of uniform standards for data collection has led to the implementation of patients’ registries through different approaches, gathering fragmented data and hampering collaborative projects and generation of evidence for translation into clinical practice. Aims: To promote basic and clinical research on RAD at the EU level by setting up a European epidemiological platform for the secure exchange and integration of RAD data, while securing patient rights in agreement with EU General Data Protection Regulation (GDPR). Method: The Rare Anaemia Disorders European Epidemiological Platform (RADeep) is an initiative endorsed by the European Reference Network on Rare Hematological Diseases (ERN-EuroBloodNet) under the frame of the European Blood Disorders Platform (ENROL), the ERN-EuroBloodNet umbrella for European patients’ registries on rare haematological diseases. RADeep is built in line with the ENROL and EU Rare Disease (RD) Platform. RADeep contributes to ENROL by sharing pseudonymised patient data. RADeep scope includes any type of RAD (ORPHA108997), including among others Sickle Cell Disease (SCD), Thalassaemia (THAL), enzymopathies and membranopathies. RAD patient data are collected from existing registries, hospital records or databases in the EU, with the aim to assess the prevalence, incidence and survival of RAD patients stratified by demographics and severity. Secondary objectives include the assessment of the main clinical manifestations and treatments of RAD subgroups. Results: RADeep legal frame of has been established in line with GDPR, enabling both entering medical data from available sources and re-use of data with third parties. RADeep solution is implemented ensuring interoperability with existing platforms based on the FAIRification of data through international ontologies (eg. ORPHA, HPO, ICD) and the implementation of SPIDER as the pseudonymisation tool provided by the EU-RD Platform. RADeep common data set (CDS) integrates 122 mandatory elements (including the 16 CDS for RD registration from EU-RD-Platform) and 38 optional, covering demographic and epidemiological data, clinical manifestations, laboratory exams and treatments. The modular structure of RADeep allows the expansion of the CDS with specific modules for research and clinical studies. The data collection is centralized through national contacts or scientific societies. Study sample size for SCD and THAL has been estimated on a mapping exercise, with a recruitment target of 20.627 SCD and 8.409 THAL patients in 15 EU countries. As of today, 10 ongoing collaborations represent the first pilots for data transfer to RADeep: Belgium, Cyprus, Denmark, France, Germany, Greece, Italy, Spain, Portugal, and Sweden, covering 89,6% and 95,4% of the estimated targets. Conclusion: RADeep offers a GDPR-compliant platform as the EU approach for the standardised collection of RAD patients data, key for the development of projects as the collaborations ongoing with GenoMed4ALL on artificial intelligence for personalized medicine, or INHERENT Network. RADeep will also provide the evidence to enhance clinical trials, guidelines and health policies that will allow better provision of healthcare to RAD patients accross EU.