Abstract :Traumatic brain injury (TBI) is a major contributor to morbidity and mortality. Few previous studies have looked at TBIs acquired from leisure-time sport activities. We report a case-series of patients with TBI in a neurosurgical ICU of Helsinki University Hospital due to leisure-time sport injury mechanisms. The patients were screened from the University of Helsinki Neurotrauma database from 2010 to 2015 consisting of 1,284 TBI patients. Outcome variables were 6-month mortality and 6-month neurological outcome dichotomized according to the Glasgow Outcome Scale (GOS). Twenty one leisure-time sport injuries with TBI were identified from the database. At the admission to the hospital, all of the patients were diagnosed with TBI of intermediate or severe difficulty. The most common etiology (12 patients) was fall from horseback. Thirteen of the patients underwent neurosurgical procedure, namely ICP sensor placement, craniotomy and evacuation of hematoma or decompressive craniectomy. Eighteen of the patients had favorable outcome in 6-month followup time. Two patients died during this time.