The present study deals with acrylonitrile-styrene-acrylic elastomer (ASA) terpolymer and an ionomer based blend to develop a weather resistant material with good heat sealability and excellent adhesion properties. The mechanical properties of ASA/ionomer blends were reduced with increase in ionomer content, whereas the thermal stability was improved. On addition of ionomer, the effects of shear rate and temperature on melt viscosity were also investigated. The mechanical modulli were also carried out to justify and correlate with ionomer content. The thermal stability, investigated by thermogravimetric analysis, showed that the thermal stability was increased with the incorporation of ionomer.