Between 6-7pm on Thursday, November 29, the 45-year-old woman was walking across the car park of the Bagshot Road supermarket when the offender wrapped his arms around her and tried to pull her to the floor.
The victim wriggled free, screamed, and the man ran away towards South Hill Park Arts Centre.
He is described as being white, of average build, with dark hair. He was wearing a black, short length, leather jacket.
Anyone who recognises the description or witnessed the incident should call 101 and ask to speak to PC Marc Boyd from Bracknell police station. To remain anonymous, call Crimestoppers on 0800 555 111.