The present study showed that when chicken is cooked using various methods, protein and all essential amino acids are affected depending on the meat part and the cooking method. Only arginine was found to be more affected by the cooking method than by the meat part (p<0.01). Overall, the protein and amino acid contents increased after cooking, and the content differences by meat part and by cooking method were found to be different in each of the samples. There was a clear difference in the protein and amino acid contents according to the meat part, and except in chicken wings, there were differences between boiling and steaming versus grilling, pan-frying, deep-frying, roasting, and microwaving. The analysis of the retention rate of each content confirmed that there was a destruction or loss of protein and amino acids during the cooking process; however, the amino acid content was higher than 100% in pan-fried wings, roasted breasts, microwaved breasts, and steamed legs. When the findings about the meat parts and the cooking methods were combined, and in consideration of the content and retention rate, roasted breast had the highest protein and amino acid contents of all the compared samples.