Anne Chaplain, 73, from Kingston Park, was last seen leaving Marks and Spencers in Northumberland Street, Newcastle city centre, at 12:20pm on Thursday.
She became seperated from her husband and he has not been able to contact her.
Anne has advanced dementia and is easily confused and vulnerable.
She is described as:
- 5 ft tall
- of Slight build
- has grey/blonde hair in a bob
- wearing a green short quilted jacket
- wearing navy trousers and black boots
- carrying a blue bag
Officers are searching the area for her and anyone who has seen her is asked to contact police.