This study investigated the effect of incorporating buckwheat (10%, 20%, and 30%) into mung bean-based extrudates on their physicochemical, textural, and antioxidant properties. Extrusion was carried out using a single-screw collet extruder at 110°C and screw speeds of 320, 350, and 380 rpm. Buckwheat addition significantly decreased lightness (L*), expansion ratio (ER), and water solubility index (WSI), while increasing redness (a*), yellowness (b*), bulk density (BD) and oil absorption capacity (OAC). Proximate composition showed some significant changes in nutritional composition. Antioxidant activity improved significantly, with total phenolic content (TPC) rising from 69.19 to 128.8 mg GAE/100 g and DPPH radical scavenging activity from 71.60 to 86.46%. Sensory evaluation showed the highest acceptability for 20-30% buckwheat formulations, particularly in colour, crispiness and overall taste. Scanning electron microscopy (SEM) revealed increased surface roughness and cross linking at higher buckwheat levels, indicating modified starch protein interactions. These findings demonstrate that buckwheat fortification enhances both the nutritional quality and sensory appeal of mung bean based extrudates, supporting its potential for developing value added gluten free snacks.