Electroencephalograms were recorded from 10 dogs before, immediately after, and every 10 minutes (for 60 minutes) after IV injection of 0.005 ml of a fentanyl citrate and droperidol combination/kg of body weight. Narcosis was adequate for recording. At 30 to 40 minutes after injection, tail wagging was the only adverse reaction (EEG artifact) observed. The only changes in EEG activity observed were a slight increase in amplitude of the dominant activity and an increase in spindle-like activity. Daily repetition for 5 days did not alter the EEG pattern or the behavior of the dogs.