The species has experienced much higher mortality levels than normal this year as the severe weather has made it hard for them to find food, the Scottish Gamekeepers Association said.
The animals have faced difficulties as their food has been buried for months under deep and drifting snow, which has then crusted over with hard frost, leaving vegetation virtually inaccessible.
Gamekeepers said people out on the hills this weekend were more likely to encounter deer than usual as in poor weather as the animals retreat from the high tops to lower ground for shelter.
Deer have not yet returned to the tops in many areas as they are too weak.
The association is urging people to try to avoid disturbing the animals and make sure dogs are kept under control.
Lea MacNally, of the Scottish Gamekeepers Association, said: “The food source is there, they just can’t get it due to the length of time there has been full snow cover. Every winter there is an expected natural mortality, but there has been much higher than normal mortality this year.
“Deer are having to expend a lot of energy scraping down through frosted snow to get to food and, in many areas, snow hasn’t lifted for a long time. The deers’ backs have not been dry for months and some calves are barely standing.
“If folk are out and about over Easter, where possible, they should try and give the deer a wide berth so as not to move them out of shelter.
“Disturbance causes deer to move and, if people take care to avoid that, it could make the difference between life and death for weakened animals.
“It would also be prudent for dog walkers to ensure their pets are under close control.”