This report serves to document research conducted under a reimbursable agreement between ARS and the Walter Reed Army Institute of Research (WRAIR), Silver Spring, MD, for “Validation of Pharmocophore Models of Mosquito Repellents”. Additional details of the research can be found in the report for the parent project 1275-32000-001-00D Manipulation of Arthropod Behavior for Protection of Humans. Quantitative structure activity relationships of chemical compounds and natural products with novel chemistries were developed and validated using a pharmacophore model. Bioassay data of different classes of compounds were key factors in refining this model. Based on this refined model, new candidates will be designed for desired specific activity for vector control. Multigram syntheses of four compounds developed using the pharmacophore model were carried out and sent for field evaluation as well as toxicological studies. A dual arm bioassay device, with optimized wind flow, was designed to evaluate spatial repellency and attraction of candidate compounds.