On Saturday, the victim was at The Star Hotel on Hoyland Road, Hoyland Common.
At 10.45pm, police were called to the venue following reports that a woman had suffered injuries to her hand.
She was taken to hospital for treatment to puncture marks to her right hand, which are suspected to have been caused by a needle.
The woman has been released from hospital and enquiries are ongoing, according to South Yorkshire Police.
Anyone with information is asked to call police on 101, quoting incident number 955 of May 25.