A telemetric study on the effects of dog harassment on released white-tailed deer (Odocoileus virginianus) was conducted at the Buffalo Springs Research Center in eastern Tennessee from May 1973 to July 1977. Thirteen female deer, 2 fawns and II adults, were released. Five deer died either directly or indirectly because of dog harassment. Three experimentally controlled dog chases involving a single chase dog averaged 2.5 km in 21 minutes. Two chases, involving both "control" and free-running dogs, averaged 5.6 km in 42 minutes. One chase involving only free-running dogs covered 1.9 km in 25 minutes before the dogs caught the deer. With over 50% of the released deer lost directly or indirectly due to dogs, dog harassment could/have a significant effect on the success or failure of deer restoration in similar areas.