This work is a fruitful collaboration between two groups of the Department Chemical, Biological and Environmental Engineering (GENOCOV and GICOM. The paper describes some recent and exciting work in the characterization of gaseous emissions from Municipal Solid Waste Treatment Facilities. We have monitored odorous compounds in several locations of three full-scale facilities using dynamic olfactometry and portable sensors. The main novelty of the work is the characterization of emissions variability throughout the day allowing 1) an analysis of potential optimization of indoor ventilation Systems and, thus, reduction of operating costs and 2) develop a multiple regression method as a simple tool for odor modeling and prediction. This work is not only useful for readers interested in the assessment of odor emissions from Municipal Solid Waste Treatment Facilities but to plant managers and the public administration to reduce costs at these facilities.