A field experiment was conducted during the rabi seasons of 2005 and 2006 to study on the effects of intercropping of babycorn (Zea mays) and rapeseed (Brassica campestris) under different levels of irrigation and mulch Results revealed that growth attributes and yield components of babycorn, is height, LAI, dry matter accumulation, number of cob bearing plants/m2, number of cobs/plant, cob length, cob diameter, green cob weight were highest in sole crop of babycorn as well as with the applications of irrigation and mulch. Similarly, in rapeseed, growth attributes and yield components such as plant height, number of siliqua/plant, number of seeds/siliqua were superior in sole rapeseed as compared with its intercropping with babycorn and application of irrigation and mulching in combination. Higher values of dehusked ear yield (1.696 t/ha) and fodder yield (3.802 t/ha) of babycorn and seed yield (1.256 t/ha) and stalk yield (2.819 t/ha) of rapeseed were obtained when the crops were grown as sole. However, application of both mulch and irrigation produced best results. The highest WUE 4.32 kg/ha/mm in sole babycorn and 6.76 kg/ha/mm in sole rapeseed were obtained along with mulch application (i.e., T3 treatment). Different competition functions like aggressivity, relative crowding co-efficient and land equivalent ratio indicated yield advantages in all the situations. The highest monetary advantage was achieved in babycorn + rapeseed intercropping alongwith irrigation and straw mulch in combination.