The solubilities of D-tryptophan in neat n-propanol, ethyl acetate, ethylene glycol (EG), n-butanol, acetonitrile, 1-octanol, and dimethyl sulfoxide and of L-tyrosine in ethyl acetate, EG, isopropanol, acetonitrile, n-butanol, and N,N-dimethylformamide (DMF) were determined via a shake-flask method at temperatures from 283.15 to 328.15 K under about 101.2 kPa. At the fixed temperature, the mole fraction solubility of D-tryptophan was the largest in EG and the lowest in 1-octanol. However, for L-tyrosine, the maximum solubility was observed in the ethyl acetate and minimum in n-butanol. X-ray powder diffraction analysis was carried out to analyze the solids equilibrated with the corresponding liquor, indicating that no polymorphic transformation or solvate formation took place in the studied systems. The solubility correlation was performed via the Apelblat equation. The obtained maximum root-mean-square deviation and relative average deviation values were 13.65 X 10(-5) and 4.32%, respectively. In addition, the solvent-solvent and solute-solvent interactions were investigated on the basis of the approach of linear solvation energy relationship.