Police hope a man's picture found on a woman who collapsed in Rockhampton's CBD earlier this week will help solve the mystery of her identity.

About 11:30pm on Wednesday police were alerted to a woman who was found collapsed at the intersection of East and Denham streets.

Vision from the Rockhampton City Council CCTV network showed the woman walking around the CBD appearing disorientated before collapsing on the footpath at the intersection.

She was taken to Rockhampton Base Hospital where she remains unconscious.

The woman was not carrying identification.

She was described as being Caucasian, aged 50 to 70, with grey hair and wearing a white t-shirt, blue cardigan, black jeans, black shoes and watch.

The woman was in possession of a set of keys that included a Toyota car key, three house keys and a plastic tab containing the photograph of a male in his early 20s.

Anyone with any information as to the identity of the woman or the man in the photo is urged to contact Crime Stoppers on 1800 333 000.