Primary immunodeficiencies (PID) are a heterogeneous group of over 300 diseases of the immune system characterised by its disfunction, and in consequence by chronic or recurrent infections, autoimmunity, allergy, neoplastic diseases or autoinflammation (1). One of the key problems at the international level is low awareness of symptoms and course of primary immunodeficiency. Based on the epidemiological data on the disease incidence, it can be estimated that ca. 70-80% of PID cases have still not been diagnosed (2). The main issue on the country level is the lack of large scale analyses concerning the actual number of PID patients in Poland, which limits the potential to streamline the disease diagnostic and therapeutic process. The following paper is an attempt to prepare a synthetic summary of epidemiological data and main problems related to PID diagnostics and therapy in Poland and to present the costs of reimbursed healthcare services related to this group of patients.