Aircraft incidents with ungulates cause substantial economic losses and pose risks to human safety. We analyzed 879 white-tailed deer (Odocoileus virginianus) incidents with United States civil aircraft from 1990 to 2009 reported in the Federal Aviation Administration National Wildlife Strike Database. During that time, deer incidents followed a quadratic response curve, peaking in 1994 and declining thereafter. There appeared to be some seasonal patterning in incident frequency, with deer incidents increasing overall from January to November, and peaking in October and November (30.7%). Most incidents (64.8%) occurred at night, but incident rates were greatest (P ≤ 0.001) at dusk. Landing-roll represented 60.7% of incidents and more incidents occurred during landing than take-off (P ≤ 0.001). Almost 70% of deer incidents had an effect on flight. About 6% of pilots attempted to avoid deer, and were less likely to sustain damage. Aircraft were 25 times more likely to be destroyed when multiple deer were struck versus a single individual. Deer incidents represented 0.9% of all wildlife incidents, yet 5.4% of total estimated costs. Reported costs for deer incident damages during this period exceeded US$36 million, with US$75 million in total estimated damages. Deer incidents resulted in 1 of 24 human deaths and 26 of 217 injuries reported for all wildlife incidents with aircraft during the reporting period. Managers should implement exclusion techniques (e.g., fences, cattle guards, or electrified mats) to maximize reductions in deer use of airfields. Where exclusion is not practical, managers should consider lethal control, habitat modifications, increased monitoring and hazing, and improved technology to aircraft and runway lighting to reduce incidents at airports. © 2011 The Wildlife Society.