MPTER is a multiple point-source Gaussian model with optional terrain adjustment. MPTER estimates concentration on an hour-by-hour basis for relatively inert pollutants (i.e., SO2 and TSP). MPTER uses Pasquill-Gifford or Briggs urban dispersion parameters and Briggs plume rise methods to calculate the spreading and the rise of plumes. The model is most applicable for source-receptor distances less than 10 kilometers and for locations with level or gently rolling terrain. Terrain adjustments are restricted to receptors whose elevation is no higher than the lowest stack top. In addition to terrain adjustments, options are also available for wind profile exponents, buoyancy induced dispersion, gradual plume rise, stack downwash, and plume half-life. Software Description: The model is written in the FORTRAN programming language for implementation on an IBM-PC compatible microcomputer. Data is in compressed format but a dearchive utility is included.