A field experiment was conducted during winter season of 2011–13 to study the influence of date of sowing and nutrient management practices for sustainable production of mustard under sub- temperate condition. The field experiment was conducted with split plot design with three replications, having 24 treatment combinations including four dates of sowing in main plot and six sub-plot treatments. Number of siliquae/plant, considerably maximum of 125.11 with 30 October sowing, and was at par with the 15 November (121.11) sowing. With respect of sub-plot treatments maximum of this parameter was found with the application of 125% RDF+PSB+Azotobacter (129.14), and showed parity with 100% RDF+PSB+Azotobacter (117.65) application. Seeds/siliqua were highest recorded with 30 October sowing, and significantly better than other sowing date except 15 November sowing. Sub-plot treatment revealed that more seeds/siliqua were registered with the use of 125% RDF+PSB+Azotobacter, and were statistically alike in response with the 125% RDF+vermicompost (@1.25 t/ha) and 100% RDF+PSB+Azotobacter. Significantly maximum seed yield of 1.21 t/ha was obtained under 30 October sowing, and was statistically at par with 15 November sowing date (1.11 t/ha). Amongst various fertility level treatments, highest seed yield was observed with the application of 100% RDF+PSB+Azotobacter (1.30 t/ha), and this was statistically comparable to 125% RDF+PSB+Azotobacter (1.26), 125% RDF+vermicompost (@1.25 t/ha) (1.15 t/ha) and 100% RDF+PSB+Azotobacter (1.04 t/ha). Economics revealed that 15 October sowing gave good returns (Rs. 20,036) and highest benefit: cost ratio (1.99). This was closely followed by 30 October sowing with benefit: cost ratio (1.98). Further, with sub-plot treatment highest net return (Rs. 30,256) were observed with the application of 100% RDF+PSB+Azotobacter with B: C ratio of 2.19.