The health enhancing effects of regular bicycling (e.g. commuter cycling) are well known, however this health benefit has also a negative aspect especially when safety is neglected. Bicyclists have a higher risk of being injured than any other group of road users. They are “unprotected” in traffic, despite being capable of reaching high speeds. This increases the risk and severity of the injury. Bicycle related injury statistics from police, hospital and insurance statistics are well described in many countries, but only give us details about serious or fatal injuries. In Belgium, it is estimated that only 15 to 30% of the cycling accidents are officially reported. To overcome this underreporting, the SHAPES project conducted an internet based online injury registration study, consisting of a Retrospective (RetroSur) and a Prospective survey (ProsSur). Since injury incidence needs to be calculated not only from the number of accidents and injuries, but also from the exposure time (= time spent cycling) a prospective study was included where participants had to fill out weekly diaries for 1 year, with information on travel frequency, distance and time spend on bicycling. During the first 10 months of online injury registration, more than 1800 participants registered on the SHAPES website. Inclusion criteria are: age between 18 - 65 years (males & females), have a paid job outside their home, cycle to work more than 2 times per week. In- and exclusion criteria for the injury registration are: accident on the route to work; acute injury; accident with corporal damage. For the RetroSur, the accident had to occur in the past 12 months before the start of the study. We present the results after 10 months data collection, during which more than 17,000 week diaries were filled out and a total of 62 accidents were considered for data analysis (ProsSur). From the 773 participants who filled out the RetroSur, 64 had an accident. The risk of having an accident while cycling to work is 8,88% for men and 6,97% for women. ...