1. The objective of the present study was to determine the apparent digestibilities of amino acids of maize, low tannin sorghum, pearl millet and finger millet in adult cockerels and Japanese quails. 2. Adult White Leghorn cockerels (25 weeks of age) and adult Japanese quails (15 weeks of age) were used to determine the apparent digestibilities of amino acids in cereal grains. 3. The digestibilities of amino acids in sorghum determined with quails were similar to cockerels, with the exception of histidine, which was significantly lower in quails. 4. In finger millet, the digestibilities of methionine and leucine were significantly higher, while that of histidine and cystine were significantly lower in adult quails than in adult cockerels. 5. The digestibilities of pearl millet amino acids were similar in quails and cockerels, except for that of histidine, which was significantly lower in quails. 6. Almost all the amino acids in maize, except histidine, had significantly higher digestibility values in quails than in cockerels. Histidine digestibility of all the 4 cereal grains was significantly lower in quails than in cockerels. 7. The amino acid digestibility values for certain cereal grains determined with cockerels do not support their use in formulating practical quail diets. The amino acid digestibility values of maize were underestimated by using cockerels while that of finger millet was overestimated.