The study was carried out in Imphal West district of Manipur with an objective to calculate the economics of rapeseed and mustard crop. The research is based on the data collected from 100 randomly selected rapeseed and mustard growing farmers. Production is normally considered as the function of area and yield. The decision regarding the choice of the crop enterprise to be taken on the farm and the allocation of area and resources under it depends to a great extent, on level of yield, price of output and the cost of inputs used in the production of that crop. The cost of cultivation and returns to different factors of production help in decision making about the selection of the crop and hence, these measures were worked out for rapeseed and mustard crop.The average cost of cultivation of rapeseed and mustard was Rs. 24208.66 per hectare. Among different components of cost of cultivation, hired human labour accounted for the large portion (28.96 per cent) followed by rental value of owned land (22.44 per cent). The net farm income per hectare was estimated at Rs.18659.60 . The benefit cost ratios per hectare was found to be 1.77.

Keyword: Cost of cultivation; Rapeseed and mustard; Cost concept; India is