The objective of the present study was to investigate the functionality of potato flour for development of cereal based snack. The blends of potato flour (10-30%), rice and maize flour were extruded at feed moisture (14%), barrel temperature (150° C) and screw speed (500 rpm). Rice and maize flour (singly and in combination), with potato flour were subjected to thermo mechanical conditions using twin screw extruder in order to elucidate their behaviour in twin screw extruder. Various parameters studied were product quality (expansion ratio, bulk density, color and hardness), functional properties (water absorption index and solubility index), pasting properties, sensory characteristics, bioactive composition (total phenolic content, antioxidant level and total flavonoid content) & in vitro starch and protein digestibility. Pasting properties of blends displayed a final viscosity ranged from 224-1281cP. Addition of potato to rice enhanced pasting characteristics whereas reverse was observed in maize blends. Higher expansion ratio was obtained for rice-potato snacks whereas no significant change was observed in bulk density of snacks. Rice-potato snacks showed higher values of hardness (56.73N) which decreased with increase in potato level. Moreover, incorporation of potato enhanced the in vitro starch digestibility. Overall acceptability of 9 was obtained for rice-potato snacks at 20% potato level.