The incident happened sometime between 11 p.m. and midnight on Thursday 17th November within the Preston Road area.
A 39-year-old man was walking in the area when he was confronted by three men as he reached the railway bridge.
At this time the men began punching and kicking the victim, who suffered a broken wrist as a result of the attack.
Inquiries are ongoing to trace those responsible and anyone with information is asked to come forward.
The suspects are described only as being white, in their twenties and had a brown staffie-type dog with them.
Detective Constable Ally Urquhart from Livingston CID said: “The victim suffered a painful hand injury during this assault and we’re in the process of trying to establish the full circumstances surrounding this incident.
“Anyone who was in the Preston Road area late on Thursday evening and saw anything suspicious is asked to contact police immediately.”
Those with information can contact Police Scotland on 101 or alternatively, the charity Crimestoppers on 0800 555 111.
DOWNLOAD THE EDINBURGH EVENING NEWS APP ON ITUNES OR GOOGLE PLAY