We have used a model accounting for absorption by vibrationally and rotationally excited ozone (O3) to examine published measurements of the quantum yield of O(1D) and O2(1Δg) from O3 photolysis in the Huggins band (305-325 nm). We conclude that the quantum yield of O(1D) is 0.2-0.3 for wavelengths between 312 and 320 nm at 298 K; in contrast, the JPL recommended quantum yield of O(1D) is negligible in this wavelength region. We present a compilation of our results at temperatures and wavelengths relevant to atmospheric calculations. Production of O(1D) from excited O3 increases calculated concentrations of O(1D) by up to 40% and OH by 15% for the troposphere and lower stratosphere. ¿ American Geophysical Union 1994