In order to maximize yield of Indian mustard (Brassica juncea (L.) Czernj. & Cosson) by optimizing sowing dates and nutrient management, a field experiment was conducted at Rajasthan Agricultural Research Institute, Jaipur, India during 3 consecutive rabi seasons (2012-13 to 2014-15). The experiment was laid out in a split plot design with four replications. The two main plot treatments comprised date of sowing (D-1: IV week of October; D-2: II week of November) and four sub-plot treatments comprised nutrient applications (T-1: RD-N40P60K40; T-2: RD-N40P60K40+RDgypsum(250); T-3: RD-N40P60K40+RDgypsum(250)+Zn and T-4: RD-N40P60K40+RDgypsum(250)+Zn + Fe). Result showed that the seed germination, seedling growth and seedling vigor index were better in D-1 sowing over D-2 sowing under control as well treated conditions. Chlorophyll content increased with the application of sulfur, zinc and iron during both the sowings, with greater magnitude in D-2 sowing. Seed yield and its contributing factors viz. days to flowering, plant height, shoot length, leaf area; primary branches per plant, number and length of siliqua were significantly and variably affected by different nutrient combinations. Application of T-3 significantly enhanced the seed and biological yield (23.13 and 74.03 q ha(-1)) (16.35% and 20.63%) over T-1, respectively, and T-3 was statistically at par with T-4. T-3 also provided the highest benefit:cost (B:C) ratio (2.14) and net returns ((sic) 38168 ha(-1)). Thus, sowing of Indian mustard in the month of October and application of RD-N40P60K40+RDgypsum(250)+Zn (T-3) is recommended to maximize its seed yield along with higher B:C ratio and returns under semi-arid conditions of India.