The quadratic model for the prediction of stability constants of transition metal (Co2+, Ni2+, Cu2+, Zn2+, and Cd2+) complexes with four monocarboxylic amino acids (methanoic, ethanoic, propanoic, and butanoic) was developed. The model yielded regression coefficient r = 0.996, and standard error S.E. = 0.05 (N = 20). As a test of goodness of the model, we predicted log K1 of three Co2+ complexes (with methanoic, propanoic and butanoic acid) from the training set (N = 17), consisted of the constants of other metal complexes and log K1 of [CoAc]+. The model yielded predictions with the S.E. = 0.08.