In order to better understand the work-related injuries sustained on central New York dairy farms, we undertook a two-year population-based study of 600 farmers and farm workers on 201 dairy farms. During the observation period, 1984-1986, 151 persons had 200 injuries, giving an injury rate of 16.6%/year (166 injuries/1,000 workers/year). Men were injured more often than women (p less than or equal to 0.01). Injured workers were older (p less than or equal to 0.01), worked more hours (p less than or equal to 0.001), and had heavier workloads than noninjured workers (p less than or equal to 0.001). The growing and harvest seasons had the most injuries; winter the fewest. More than 2/3 of the injuries occurred in the afternoon. Owners/operators, often the most experienced, knowledgeable people on the farms, were most often hurt. Those working more than 60 hours/week, with greater than 30 acres under tillage/worker, had a relative risk of 2.76 compared with all other workers. The attributable risk for this group was 51%. There were two fatalities, both involved owner/operators. Our findings suggest that previous studies may have underestimated the risks faced by farmers. Dairy farming in central New York is very dangerous work. Those who own and operate these dairy farms are most often hurt and killed. Analysis of events on individual farms will be reported separately.