Detectives are appealing for information following the robbery within Johnstone High School car park, off Beith Road at 11.30pm on Sunday, May, 23.
The 23-year-old man was meeting up with a woman in the car park at the time.
She is described as heavy build, aged 40-50s, with some missing teeth, blonde/brown hair in a ponytail.
She was wearing a grey jumper and was driving a small white car.
While speaking to the woman, the victim was approached by three men wearing dark clothing, masks and gloves.
These men then assaulted him and stole his car keys.
The 23-year-old sustained a minor facial injury and was very shaken as a result of the robbery, according to Police Scotland.
Police Scotland said enquiries are ongoing.
Police are keen to speak to the woman who spoke to the victim in the car park and have asked anyone with any information to come forward.
Detective Constable Jade Clark of Paisley CID said: “Our enquiries are continuing to identify and trace the three men involved and we are also keen to get in touch with the woman who spoke to the victim.
“Anyone with any information that will assist our investigation should contact Paisley CID via 101, quoting reference 0012 of 24 May. Alternatively, Crimestoppers can be contacted on 0800 555 111, where anonymity can be maintained.”