Field experiment was conducted to cultivate brinjal (Solanum melongena L.) grafts and determine the fertilizer use efficiency as well as the cost economics of brinjal grafts under different spacing and fertigation levels. A strip plot design was adopted with four levels of spacing (1 m x 1m, 2 m x 1 m, 1.5 m x 1.5 m and 0.6 m x 0.6 m) and three levels of fertigation (75, 100 and 125 % RDF) replicated four times. Seedlings (non-grafted brinjal) were planted for comparison with grafts under main crop evaluation. After six months, the plants were pruned to obtain ratoon crop which was maintained for four 4 months. Fertilizer use efficiency was also worked out for all the treatments. The treatment 1 m x 1 m + 100 per cent RDF recorded the highest net income of ` 3,40,585 ha-1 with benefit cost: ratio of 2.62:1 and FUE of 245.00 kg kg-1 in main crop while in ratoon crop the net income was` 1,61,525 ha-1 with benefit: cost ratio of 2.19:1 and fertilizer use efficiency of 132.04 kg kg-1. Cost economics for all the treatments was worked out on the basis of the incurred input cost and market price of the produce at the time of experimentation. In seedlings, the net income was ` 92,422.00 ha-1 with benefit: cost ratio of 1.53:1 and fertilizer use efficiency of 118.26 kg kg-1