2'-Benzoyloxycinnamaldehyde (BCA), a derivative of 2-hydroxycinnamaldehyde demonstrated a potent antitumor effect against several human solid tumor cell lines. The physicochemical properties and degradation kinetics of BCA were investigated to support the drug-development effort. The aqueous solubility of BCA was low, and it was not considered to be hygroscopic. The degradation of BCA followed the first-order kinetics, and the pH-rate profile revealed that the degradation of BCA was governed by general acid- and specific base-catalysis as well as spontaneous hydrolysis. BCA was very unstable in basic conditions, in particular pH above 9, and found to be more stable in acidic conditions such as pH between 2 and 4. The degradation of BCA was accelerated in elevated temperature and high-ionic strength. Therefore, it was suggested that BCA should be stored in slightly acidic conditions with lowered temperature and ionic strength.