The incident happened in Fleming Way, at the junction with Fritillary Court, at around 7.45pm on Saturday evening (11/12).
The victim, a man in his 50s, reported that he was attacked by a man who appeared to be intoxicated and seemed to want to steal his mobile phone.
During the assault the victim was hit over the head and kicked after he fell to the floor.
He managed to call police, who attended and carried out a search of the local area.
Officers took him to Great Western Hospital, where his injuries were confirmed.
At this stage no arrests have been made but our enquiries are continuing and we are appealing for anyone with information to come forward.
Any witnesses should call Swindon Community Policing Team on 101, quoting crime reference 54210120751. Alternatively you can call Crimestoppers anonymously on 0800 555111.
