Kusoldharm rescue workers were called to the scene, a curve near the quiet beach, at 6:46pm.
The man, a 49-year-old from New South Wales*, was under the right side of truck. His motorbike was on the ground on the left side of the truck.
A helmet was found at the scene, but the man had suffered severe trauma. His body was taken Patong Hospital.
Phuket Tourist Police reported that the man checked in alone at the Baan Laimai Patong Beach Resort on Monday (Mar 27) and was due to check out tomorrow (April 1).
He had rented the Honda Click motorbike from a shop in Soi Kebsup, behind the Laimai Hotel.
Tourist Police said they had yet to receive details of the investigation into the accident, but named the cement truck driver was named as Sakon Sriprasit, 39.
Patong Police did not answer calls from The Phuket News this morning.
The Australian Consulte in Phuket has been notified of the man's death.
* The Phuket News is withholding the man's identity until it has been confirmed that his next of kin have been notified.