An experiment was conducted at the Department of Agronomy Experimental Farm, Delta State University, Asaba Campus in 2011 early and late cropping seasons to evaluate the effects of fish pond effluent and inorganic fertilizer on amranthus performance. The study had five levels of fish pond effluent (0, 5, 10, 15 and 20t/ha) and five levels of inorganic fertilizer (0, 100, 150, 200 and 250 kg/ha), laid out in randomized complete block design with four replications. Number of leaves, leaf area, plant girth, leaf fresh weight, stem fresh weight, marketable yield and dry matter yield were measured. Soil samples were taken before and after harvest of late season for soil chemical evaluation. Data were subjected to analysis of variance and means differences were separated with DMRT at 5% level of probability. Results revealed that fish pond effluent and inorganic fertilizer had positive effects onamaranthus. The 250 kg/ha of NPK produced the highest leaf fresh weight, stem fresh weight and marketable yield while 20 t/ha of fish pond effluent had highest dry matter yield at both seasons. Also, 20 t/ha of fish pond effluent had higher effects on soil chemical properties than the NPK fertilizer. It is therefore recommended that 20 t/ha of fish pond effluent be applied in Asaba and its environs.