Absolute O(D-1) quantum yield from the photodissociation reaction of O-3 at 308 nm should be determined accurately with high precision for its atmospheric significance. This is because it has been used as a reference in previous relative measurements to obtain the O(D-1) quantum yields as a function of photolysis wavelength in the near-UV region. In this study, the near-UV pulsed-laser photolysis Of O-3 with the direct detection of the O(D-1) and O(P-3) photofragments using a technique of vacuum UV laser-induced fluorescence has been applied to determine the absolute O(D-1) quantum yield from O-3 photolysis. The absolute O(D-1) quantum yield at 308.0 nm at room temperature (298 2 K) is determined to be 0.804 +/- 0.048 (95% confidence interval), in which the uncertainty is much smaller than the values recommended for use in atmospheric studies. The O(D-1) quantum yield values at photolysis wavelengths between 307 and 311.5 nm are also presented.