India is the world’s second-largest producer of groundnut (Arachis hypogaea L.), accounting for 31.81% of the country’s oilseed production. Despite advances in mechanization, threshing remains a labor-intensive process, requiring 160-200 man-hours per hectare. To address this, a power-operated groundnut thresher was developed and evaluated at SVCAET&RS, IGKV, Raipur. The study examined the effects of three operational parameters cylinder peripheral speed (23.5-31.5 m/s), feed rate (7700-7900 kg/h), and concave clearance (15-25 mm) on threshing efficiency, cleaning efficiency, broken pod percentage, and un-threshed pod loss. Experiments followed a three-factor factorial randomized block design (FRBD) with three replications, ensuring statistical reliability. Standard testing procedures (IS: 11234-1985 and IS: 6284-1985) were used for performance evaluation. Results demonstrated that optimized combinations of speed, feed rate, and clearance significantly enhanced threshing and cleaning efficiency while minimizing losses, highlighting the thresher’s potential to reduce drudgery and improve post-harvest efficiency in groundnut cultivation.