The aim of this article is to examine organizational factors influencing serious occupational accidents. The study was part of a larger project investigating 99 serious occupational accidents in southern Finland. A workplace analysis and an accident analysis were done at accident sites. In connection with this investigation, 73 victims, 91 foremen, and 83 co-workers were interviewed with a structured questionnaire. The results showed that the need to save time, tight schedules, and a lack of caution had a greater influence on accidents than did the foremen, co-workers, customers, professional pride, curiosity, or the wage system. Big companies had the lowest risk of serious occupational accidents. Accident risk was significantly greater for subcontractors than for main contractors.