A field experiment was conducted on sandy loam soil during rabi season of 1999–2000 to study the effect of four levels of nitrogen (25, 50, 75 and 100 kg ha −1) and two sources of biofertilizer viz., Azotobacter (A 1) andAzospirillum (A 2) on yield and quality of onion bulb (Allium cepa L). Results indicated that the application of nitrogen @100 Kg N ha −1 significantly increased bulb yield and quality attributes. The treatment combination N 4A 1S 2 (100 kg N ha −1 + Azotobacter with seedling dipping) gave highest bulb yield and fresh weight of bulb, followed at par by N:AIS 2 (75 Kg N ha −1 + Azotobacter with seedling dipping). In economics, the maximum B:C ratio (2.26:1) was recorded with the treatment combination of N:AIS 2 as compared to N 4A 1S 2 with a lower B:C ratio (2.24:1) due to additional cost of urea and non significant difference between these two treatments regarding yield of bulbs. Thus, the treatment combination N 3A 1S 2 was the best.