Angela Gow, 52, left her home in Kirkmichael Road, Helensburgh, at 7am on Monday.
When she failed to return home that evening, her family contacted police.
Angela is around 5ft8in tall with a slim build.
She has straight, black collar-length hair and blue eyes.
Extensive enquiries are being carried out, with officers contacting family in Drumchapel and checking CCTV in an effort to locate her.
However, so far all attempts to find her have proved unsuccessful.
Angela is currently on medication, however it's not known if she has her medication with her and police are concerned for her wellbeing.
It is also understood she may be dealing with some personal issues.
Sergeant Eric Jardine said: "I am appealing to anyone who may have seen Angela to get in touch with us.
"Her family is extremely concerned and want to know she is safe and well."
Anyone with information is asked to call the non emergency number, 101.