Previous studies have reported that tractors are responsible for high proportions of fatal and nonfatal agricultural injuries. However, many common and preventable risk factors, conditions, and associated costs related to tractor-related injuries have not been investigated. This case-based study used workers' compensation data to investigate tractor-related injuries. The objectives of this study were to (1) identify and describe tractor-related injuries, (2) assess medical and indemnity costs associated with tractor-related injuries, and (3) determine contributing factors associated with those injuries. Tractor-related injury claims data from Colorado workers' compensation records were analyzed for a 12-year period (1992-2004). Descriptive analyses of the costs, characteristics, and contributing factors associated with tractor-related injuries were conducted. The epidemiological agent-host-environment model was used to analyze injury event descriptions. A total of 23,484 agricultural-related injury claims were analyzed. Through an event description analysis, a total of 642 claims were identified as being tractor-related. Over 60% of tractor-related claims involved sprains/strains and contusions. A total of 21% of tractor-related claims were associated with the worker mounting or dismounting a tractor, and an additional 10% of claims were associated with the worker falling, jumping, or slipping off a tractor. Among all claims associated with tractor mounting or dismounting, 35% involved the ankle and 15% involved the knee. Nearly three-quarters of tractor-related claims were medical-only claims. The median medical claim cost was $319, and the median medical plus indemnity claim cost was $335. Claim costs associated with tractor-overturn injuries were higher than tractor-related injury claims in general. This study determined that a large percentage of tractor-related injury claims were associated with tractor mounting and dismounting. These findings are consistent with previous research and suggest the need to further investigate tractor design criteria related to mounting and dismounting.