The photocatalytic decomposition of salicylic acid with visible light in an oxygenated aqueous suspension of colloidal alpha-Fe2O3 particles has been studied. About 10-20 ppm of this organic is degraded within 1 h of irradiation, depending upon the initial salicylic acid concentration. Kinetic parameters have been investigated in terms of a first order rate equation. The rate constant (k(ap)) for this heterogeneous photocatalysis was evaluated as a function of the initial concentration of salicylic acid. Carbon dioxide has been detected over prolonged visible light irradiation.