We examined the use of dog shock collars on 2 different wolves (Canis lupus) over a 4-year period to assess whether this system could be used to reduce wolf depredation on livestock. In 1998 we used human-induced shock and determined that the shock collar could keep a depredating wolf off a farm while maintaining normal den- and rendezvous-site attendance, but it did not seem to have a long-term effect on the wolf's behavior. In 1999 we captured a wolf prior to any depredations and used a command center with a beeper that remotely shocked the wolf while also providing aversive stimuli; no depredations occurred in 1999. We used the beeper unit alone in 2000, when only 2 calves were killed. A second wolf was captured in 2001 after depredations began, and although it was kept off the farm, other pack members caused further depredation and were removed from the farm. It appears that in some situations shock collars with a command center and beeper device may be useful for reducing wolf depredations, but more research is needed.