The study were conducted by cluster frontline demonstrations (CFLD) on mustard during 2018-2021 in the eleven villages covering 250 farmers and 100 ha area of Banka district of Bihar to evaluate the technological interventions, yields and economic feasibility. Yield parameters i.e., plant height, primary, secondary branches/plant, siliqua/plant, seeds/siliqua, siliqua length, dry matter/plant and 1000-seed weight were recorded 219, 4.3, 13.8, 743, 13.5, 5.2, 123 and 5.7, respectively in mustard cv. RGN-48 along with improved practices in comparison to the farmers' practices. Significantly higher grain yield (1508 kg/ha) was recorded under demonstrated plots over farmers' practice Extension gap (3.92), technology gap (11.30), technology index (42.82%) and adaptation rate (38.33%) were markedly recorded under the demonstration plot than farmers' practice. Similarly gross (Rs. 66820) and net returns (41250) obtained in demonstration plots than farmer's plot. With the adoption of a better set of techniques as developed by the cluster frontline demonstration at the farmers' fields, crop yield and financial returns of mustard increased. Awider viewpoint of farmers was persuaded to implement the intervention by the demonstrations' improved economic feasibility