Pneumatic fracturing is an innovative technology enhancing the removal and treatment of contaminants in moderate-to-low permeability formations. The main advantages are a reduction in treatment time and the extension of available in-situ technologies to more difficult geologic conditions. Pneumatic fracturing has been successfully demonstrated in the field at a number of contaminated sites and in a variety of geologic formations. The technology is now commercially available and is being incorporated into site cleanups. This article provides an overview of the pneumatic fracturing technology, beginning with a general description of the concept and apparatus. Next, key technological considerations will be discussed including fracture initiation, fracture orientation, fracture flow, and treatable soils and contaminants. Three case studies are presented describing different applications of pneumatic fracturing. The article concludes with a discussion of cost benefits of the technology.