This study evaluated the effect of disinfection methods on the dimensional stability, flexural properties, and microhardness of a heat-polymerized denture acrylic resin. A1- and 12-hour immersion period in 2% alkaline glutaraldehyde, and 3- and 15- minutes exposure to microwaves were employed as disinfection or sterilization procedures. Storage in water for 1 and 12 hours were used as the control. For each procedure 10 specimens were used. The results indicated that the linear changes observed were of no clinical importance. The same conclusion can be drawn for flexural properties and microhardness. The microwave method is a useful alternative to immersion disinfection.