This review provides a general overview of microwave applications in oil sands bitumen or shale oil production in petroleum upgrading. The vast oil reserves in the oil sands of Alberta will become a major source of petroleum products in the near future and a number of alternative technologies have been explored for the production and upgrading of oil sands and heavy oil. This study is based primarily on the unique selective heating capacity associated with exposure of materials to microwaves. Of particular interest are applications of microwaves for bitumen extraction, upgrading heavy oils, removing heteroatoms, and the underground heating of oil sands to reduce bitumen viscosity and allow it to be pumped to the surface. The fundamentally different method of transferring energy from the source to the sample is the main advantage of utilizing microwave energy. By directly delivering energy to microwave-absorbing materials, conventional issues such as long heating periods and energy loses can be minimized. Microwave energy was shown to be effective in some applications; however, it is not used commercially at the present time. (C) 2009 Elsevier B.V. All rights reserved.