Launceston Police are investigating a serious assault in the Mayfield area in the early hours of this morning.

About 3.50am police were called to a report of a 30-year-old male who had suffered serious but non-life threatening injuries in an assault.

The man is undergoing surgery at the Launceston General Hospital.

Police believe the victim and offender are known to each other.

Information can be provided anonymously by calling Crime Stoppers on 1800 333 000 or online at crimestopperstas.com.au