Helicopters are used for numerous wildlife management and research purposes, but can alter wildlife behaviour and influence baseline data collection. We investigated reactions of GPS-collared moose Alces alces and brown bears Ursus arctos to short-term helicopter approaches by researchers. Moose responded with up to 10 times greater movement rates for up to two hours following a helicopter approach and moved into more rugged terrain. Brown bears decreased their speed and remained within similar habitat types and terrain. The movements were influenced only about two hours and did not influence the size of the activity areas. Contrary to our predictions, brown bears responded with a somewhat calmer response than moose, illustrating response differences in large herbivores and carnivores. This difference in response might be because brown bears are actually less disturbed than moose by direct helicopter approaches or because of a difference in tactical behaviour between brown bears and moose following disturbance. Researchers and managers should thus be cautious in using knowledge from one species to predict or perceive disturbance response in another species or taxa.