The aims of this article were, on the one hand, to indicate the risk groups exposed to serious occupational accidents and, on the other hand, to examine what makes serious occupational accidents 'serious'. We compared the data on 99 serious occupational accidents gathered by ourselves to the information from official statistics. The results showed that the risk of a serious accident was highest for a man working in the manufacturing industry, at a construction site, or in transporting, and who was in his first year of service. Typical serious occupational accidents were falls from heights, accidents with machines, and getting run over by moving vehicles. The most general injuries were fractures, loss of extremities, and injuries to internal organs. Serious occupational accidents differ from minor accidents as regards type of accident and injured part of the body.