<p>Sugarcane is a major cash crop in Nepal, but its production and yield remain low due to multiple constraints. This study assessed technology adoption, resource use efficiency, and technical efficiency among 241 sugarcane farmers in Nawalparasi (West), Nepal, a key sugarcane-producing area facing a massive decline in cultivation despite having favorable conditions. Using a cross-sectional survey and analyzing data with the Cobb–Douglas production function and stochastic frontier model, resource use and technical efficiencies were calculated. The average technology adoption index was 0.59. High adoption was observed for land preparation (93%), application of DAP (72%), and split application of urea (91%), while planting time (69%) and sett treatment (61%) had moderate adoption. Decreasing returns to scale were found for both the plant crop (0.576) and the combined plant + ratoon crop (0.835). To reach optimal returns for the plant crop, costs for sett, land preparation, fertilizers, labor, irrigation, and plant protection inputs require an increase of 38.8, 69.6, 26.0, 85.0, 99.8 and 78.6% respectively. Farmers’ plant and ratoon crop yields show a smaller yield gap with the national average, whereas the yield gap with experimental and potential yields is huge. Technical efficiency averaged 88.4% for the plant crop and 89.8% for the plant + ratoon crop, indicating potential yield improvements through better resource use. Key input factors affecting output included sett, soil preparation, and chemical fertilizers, whereas inefficiencies were linked to cooperative membership and landholding size. The findings highlight the importance of targeted interventions that ensure an increase in the rate of technology adoption and optimum use of resources.</p>