The Urban Airshed Model and user's guide consists of five volumes: (one volume per magnetic tape) (1) Model description and a user's manual describing how to run the core model using pre-prepared air quality, meteorological, topographical, and emissions input files. (2) A summary description and user's manual for all UAM preprocessor programs and their input requirements. These preprocessors can be used to generate the input files needed to run the core model described in volume 1. (3) The Diagnostic Wind Model (DWM) user's manual contains a detailed description of the DWM (summarized in volume 2), its underlying rationale and input requirements. The DWM is used to generate three dimensional wind fields. (4) The Emissions Preprocessor System (EPS) user's manual contains a detailed description of the EPS (summarized briefly in volume 2), including required emission inputs and their format. A description of the biogenics emissions processor, its operation and how it is eventually merged within the manmade area sources emissions file to produce the gridded, hourly speciated emissions data required by the core model, is contained in volume IV as an appendix. (5) ROM/UAM Interface Program System user's manual describes procedures for using Regional Oxidant Model (ROM) simulations to generate required air quality, meteorological, and biogenic emissions files to operate the UAM core model described in volume I.