Two broiler feeding trials (1-31 days of age) were carried out to determine the effect of fortifying grain amaranth diets with lysine, methionine, casein and ethylene diamine tetraacetate (EDTA) on performance, amino acid availability, plasma amino acids, nitrogen and mineral retention. In Trial 1, lysine, lysine plus methionine and casein were separately included in six diets containing either 400 g/kg raw or 600 g/kg extruded amaranth. Additionally, one 400 g/kg raw and one 600 g/kg extruded amaranth diets were not fortified. The eight diets were compared to a maize-soyabean meal control diet. Chicks on the 600 g/kg extruded amaranth diet with casein gave similar body weight to that of the control. Feed intake, and nitrogen retention were similar between the control and the extruded amaranth diets. Chicks on the control diet gave the highest amino acid availability values. Lack of response from lysine or lysine and methionine inclusion indicated that these amino acids were not limiting to growth in the amaranth diets. In Trial 2, three diets had 400 g/kg raw while three had 400 g/kg extruded amaranth. Two diets in each group were fortified with either disodium ethylene diamine tetraacetate or casein while the third was unfortified. Casein inclusion resulted in higher body weights but did not affect the plasma levels of essential amino acids. Dietary EDTA did not enhance the body retention or the plasma concentration of minerals. From the two trials, fortification of amaranth diets with casein improved chick performance and amino acid availability.