Field experiment entitled “Effect of nano urea on growth, yield and quality of Indian mustard [Brassica juncea (L.)]” was conducted at School of Agricultural Sciences, JRNRVU Dabok, Udaipur during rabi seasons at 2023-24 to study the effect of nano urea on growth, yield and quality of Indian mustard. The experiment consisting ten treatments- T1 (control), T2 (100% RDN), T3 (75% RDN), T4 (50% RDN), T5 (50% RDN + Nano urea 2ml l-1 ), T6 (50% RDN + Nano urea 4ml l-1 ), T7 (50% RDN + Nano urea 6ml l-1 ), T8 (75% RDN + Nano urea 2ml l-1 ), T9 (75% RDN + Nano urea 4ml l-1 ) and T10 (75% RDN + Nano urea 6ml l-1 ). These treatments were evaluated under randomized block design with three replication. Treatment T10 (75% RDN + Nano urea 6ml l-1 ) significantly increase plant height at 30 DAS and 60 DAS, dry matter accumulation at 30 DAS, 60 DAS, 90 DAS and at harvest, number of branches plant-1 , number of siliqua plant-1 , number of seed siliqua-1 , length of siliqua, 1000-seed weight, respectively. The application of 75% RDN with nano urea 6ml l-1 resulted in significant increase in seed yield (1995 kg ha-1 ) by 33.0% and 17.2% over T1 (control) and T3 (75% RDN) but was at par with T2 (100% RDN). Similar trends were observed with stover yield and biological yield. However, it did not cause any significant increase in secondary branches plant-1 and harvest index (%).