An integrated puff model, INPUFF, is evaluated using the MATS data base. A description of the model is provided outlining the salient characteristics. A brief description of the MATS data base, which consists of 14 SF6 tracer releases with associated meteorology, is also provided. INPUFF slightly overestimated peak concentrations. Since the SF6 puffs were well mixed for every tracer release, model performance is very sensitive to estimates of the mixing heights. The absolute mean fractional error between two techniques for estimating the mixing height was 0.87, which indicates a large uncertainty in the very important input parameter.