Broad Leaf Mustard, one of the most popular, highly commercialized, and widely grown green vegetables due to its richness in vitamin and minerals with peculiar taste. The precise knowledge of ideal planting time with right selection of variety provides suitable environmental conditions at all growth stages that increase the yield. The field experiment was carried at Horticulture Farm, Faculty of Agriculture, Agriculture and Forestry University, Rampur, Chitwan to evaluate the effect of transplanting dates on growth, yield and quality of Broad Leaf Mustard (Brassica juncea L. var. rugosa) varieties in Terai condition of Nepal during October 2021 to March 2022. The experiment was laid out in two factorial randomized complete block design (RCBD) with three replications. There were sixteen treatment combination comprising four varieties (Khumal Broad Leaf, Marpha Broad Leaf, Manakamana and Mike Giant) with four transplanting dates (October 25, November 9, November 24 and December 9). The results revealed that transplanting dates and varieties along with interaction significantly influenced the growth, yield and quality of Broad Leaf Mustard. Among the varieties, Khumal Broad Leaf was significantly superior on growth parameters like plant height, leaf length and breadth, plant canopy but on yield attributes the superior variety was Mike Giant based on number of leaves harvested per plot (226.08) and leaf yield (26.43 mt ha-1). However, the organoleptic test result revealed that the Mike Giant had excellent taste (74%) along with highest recovery percentage of Gundruk (27.62 %). Among the date of transplanting, mid transplanting on November 9 was better in terms of growth and leaf yield of 28.92 mt ha-1. While poorest performance was recorded on last transplanting on December 9 in all growth, yield and quality parameters with leaf yield of 17.36 mt ha-1. The interaction effect of different varieties and transplanting dates resulted better growth and quality in Khumal Broad Leaf and Manakamana varieties when transplanted on November 9. So based on the results of the experiment, Mike Giant transplanted on November 9 produced better growth and yield than others for the optimum yield production in Chitwan, Nepal.