In the present study, data of bicycle crashes leading to medical attendance in acute hospital or to death which occurred between June 1st 2004 and May 31st 2006 were analyzed. The final results consisted of injury data and patient records obtained from Kuusankoski Regional Hospital and from the road accident investigation teams. The total number of cases was 216. The severity of the injuries was classified according to the Abbreviated Injury Scale (2005). The majority of the bicycle crashes considered occurred when the injured was alone, without another party. Crashes were often alcohol-related (31%). Over one third of all cyclists’ injuries were head injuries. Only 13% of the injured cyclists wore a helmet. 15% of those who wore a helmet sustained a head injury and, correspondingly, 43% of those who did not. Two bicyclists died. The number of bicycle crashes in the hospital data was at least fourfold compared to the number found in the official police statistics. Systematic collection of data on bicycle crashes in hospital emergency departments should be advanced in order to gain reliable information for prevention.