Justina Kolberg has not been in contact with anyone since early on Wednesday afternoon.
Rescuers are searching for a walker missing overnight in the Cairngorms
It is believed she planned to climb Ben Macdui.
Police said mountain rescue teams and a helicopter have been searching the area and appealed for information.
The missing woman, alderen 32, is described as white, 5ft 7in tall and of slim build, with blonde hair.
When last seen, she was wearing a blue jacket, black trousers and was carrying a black rucksack.
Sergeant Craig Johnstone, of Aviemore police station, sa: “We believe that Justina headed to the ski centre around 8am on Wednesday morning and headed off to climb Ben Macdui in the Cairngorms.
“She has not been in contact with anyone since about 2pm on Wednesday and we are concerned for her safety.
“Officers have been carrying out inquiries to trace her and searches have been ongoing in the local area and on Ben Macdui involving mountain rescue teams and the Air Support Unit.”
Anyone with information is asked to contact police on 101 with reference 3004 of January 26.