The reaction of OH with acetaldehyde in the gas phase has been studied by tunable infrared laser kinetic spectroscopy. As expected, the main channel is the production of water (similar to100%). An upper bound of 5% was placed on the yield of CH3, and the yield of H is estimated as 5 +/- 5%. A rate constant of 1.67(10) x 10(-11) molecules(-1) cm(3) s(-1) is obtained for the title reaction, in good agreement with previous measurements. The major product of the reaction, CH3CO, reacts with O-3, producing CH3, CO2, and O-2 in one channel with a rate constant of 1.4(5) x 10(-11) molecules(-1) cm(3) s(-1) and producing CH3CO2 and O-2 in the other channel with a rate constant of 3.3(5) x 10(-11) molecules(-1) cm(3) s(-1).