This study determined the effects of Sesbania grandiflora (SG) leaf extract on the growth, feed utilization efficiency and non-specific immunological responses in black tiger shrimp (Penaeus monodon). Three diets were prepared by mixing the methanol extract of SG onto a pellet feed (34% protein) at concentrations of 0% (control), 0.05% (T1) and 0.1% (T2), respectively. Ten shrimps (mean weight 2.1g), were reared in each tank of 80 L, and the weight and immunological reaction of shrimp were received after a feeding trail of 28 days. The dietary extract treated shrimp had better growth performance (WG, SGR), and feed utilization efficiency (FCR, PER) compared to the control group. The treated shrimp exhibited enhanced immunological responses; the total haemocyte count, prophenoloxidase activity, superoxide dismutase activity, and shorter haemolymph clotting time compared to the control shrimp. In conclusion, a lower level of SG (0.05%) was found to be most effective in terms of immune response enhancement; hence, this plant could be a good source for feed additives for enhancing sustainable shrimp production.