ObjectivesThe aim of this study was to evaluate the cost of surgical treatment for primary ulnar nerve entrapment (UNE) borne by the public sector in Finland.DesignRegistry-based cost description study.SettingPrimary and secondary care throughout Finland.ParticipantsWe identified all the patients diagnosed with primary UNE in the whole population of Finland from 2011 to 2015 from the Care Register for Health Care. From these patients, we identified those who had undergone ulnar nerve release during the year they were diagnosed or the following year.InterventionsOpen ulnar nerve release.Outcome measuresThe primary outcome measure was cost borne by the public sector in 2015 euros. The cost of surgery was based on the diagnosis-related group prices. We calculated the cost of a single visit to a primary care physician, an electroneuromyography examination, a preoperative visit to a hand surgeon and a follow-up appointment by telephone in specialised care for each patient. These unit costs were provided by the Finnish Institute for Health and Welfare and the same costs were used for each patient. We obtained the number of reimbursed sick days and the total amount reimbursed to each patient in euros within the 2 years after diagnosis from the Social Insurance Institution of Finland.ResultsDuring our study period, approximately 1786 primary UNE diagnoses were made yearly, and on average, 876 (49%) of patients received surgical treatment annually. The surgery-related cost per patient averaged at EUR 1341 (43%) and reimbursed sick leaves at EUR 952 (30%) during this period. The annual cost of surgical treatment for UNE borne by the public sector in Finland varied between EUR 3082 and EUR 3213 per patient.ConclusionsThe average cost of surgical treatment for UNE in Finland was EUR 3140 per patient between 2011 and 2015.