To identify potential safety improvements to combine harvesters, the present study analyzes survey data regarding accidents involving combines. A questionnaire survey was completed by 902 Japanese farmers who had been involved in combine harvester accidents; the respondents were from 23 different prefectures. The questionnaire included items such as degree of injury, cause of accident, and machinery operation conditions. The survey results found 257 accidents, including 134 injuries and two fatalities. The data include specific accident causes for 242 cases. According to the results, 65% of combine accidents were caused by contact with processing parts such as the cutter, feeding chain, or conveyer belt, while 29% were caused by the combine rolling over. In the former cases, 60% of victims were seriously injured and either visited or were admitted to a hospital; roughly 2/3 of these serious cases stemmed, at least in part, from a deliberate deviation from safe operating procedures. Both fatalities reported were caused by combines rolling over, but no one was injured in 80% of the rolling accidents reported. The most common occurrences of combines rolling over included combines rolling off transport trailers or rolling off gangways connected to truck platforms. More accidents occurred while transporting combines than during operation. These results suggest that equipment improvements to harvester combines that prohibit deliberate deviations from safety procedures as well as improvements to avoid machinery rolling over are required. Language: ja