EMERGENCY services in Shetland were called out to Laxo in the north mainland on Thursday afternoon after police received reports of a missing person.
Lorraine Grains, from Vidlin, is described as white, about five foot two in height and of slim build.
She has long purple hair and is believed to be wearing black leggings or jeans and a long black overcoat.
Lerwick lifeboat is checking the coastline of Dales Voe, while police officers are searching the nearby area. The Coastguard helicopter is also involved in the search.
Police sergeant Chris Hardwick said: "Officers are concerned for the welfare of Lorraine and are appealing to members of the public who may be able to offer any information as to her current whereabouts."
Lerwick police station can be contact on telephone 101.