Experiments were conducted to investigate the effects of feeding high tannin (HT) and low tannin (LT) sorghums in sorghum-soybean meal diets first limiting in methionine (Met) and in sorghum-soybean meal-safflower meal diets first limiting in lysine (Lys) and second limiting in Met. With the diets first limiting in Met, HT sorghum greatly reduced growth rate as compared to LT sorghum, and this reduction could be completely overcome by Met supplementation. In contrast, with diets first limiting in Lys, HT sorghum did not depress growth rate. Results of Lys and Met supplementation of LT sorghum diets corresponded to expected responses to first and second limiting amino acid additions; whereas neither Lys nor Met alone significantly influenced growth in HT sorghum diets, but supplementation with both amino acids elicited a response. It would appear that HT sorghum preferentially influenced Met utilization to a point where Met and Lys became equally limiting in the HT sorghum-soybean meal-safflower meal diet. Chicks fed HT sorghum-soybean meal diets and orally dosed with either 14CH3 or 14C-3 labeled Met excreted 1.5 × more radioactivity during the following 24 hours than did chicks fed LT sorghum regardless of the position of the label. In a digestibility trial, nitrogen retention, dry matter utilization, and nitrogen digestibility were all significantly lower in chicks fed an HT sorghum-soybean diet. Methionine supplementation did not significantly influence any of the parameters measured in chicks consuming the LT sorghum diet. In contrast, a significant increase in nitrogen retention and dry matter utilization was noted in chicks fed the HT sorghum diet supplemented with methionine. However, nitrogen digestibility was apparently unaffected.