A research project was undertaken to study the effectiveness of soil vapor extraction (SVE), an emerging technology for remediation of soils contaminated with volatile organic compounds (VOCs). As part of the project, two soil vapor extraction systems, Site D and Site G at the Twin Cities Army Ammunition Plant, New Brighton, Minnesota were selected for evaluation. The approach of the project was to gather and compare site information regarding residual soil concentrations before and after treatment, and obtain operational data to evaluate the performance of the systems. The residual levels of volatile organics before and after treatment are compared for magnitude and distribution. Operational data are analyzed to present the performance of the systems and the progression of treatment with time. Capital, operating and maintenance costs are presented. Results of the evaluation indicate that SVE has been effective in reducing the residual concentrations, generally by several orders of magnitude. In most cases, residual concentrations were nondetectable. Samples taken in silty clays and waste materials showed the hightest residual concentrations.