Recognizing the need for consistent, reliable, and efficient methods to collect information about the walking environment, the authors have developed and tested a complete environmental audit methodology—the Pedestrian Environmental Data Scan (PEDS). In this paper, the development of the audit methodology is presented, including the design of the instrument, the creation of training and supporting materials, administration, and integration with handheld technology. Various tests of inter- and intra-rater reliability of our instrument have been conducted, including individual audit measures and various approaches to administering the audit. The results indicate high reliability for most measures and confirmed administration procedures. The PEDS audit methodology provides a comprehensive method to evaluate pedestrian environments for academics involved with transportation and physical activity research as well as practitioners seeking to an assessment tool for prioritizing investments.