The quenching of the excited state of the uranyl ion by aliphatic alcohols has been studied under conditions where the luminescence decay is bi-exponential. In agreement with previous reports, the quenching is strongly dependent on the type of alcohol, and shows a marked deuterium isotope effect. This is consistent with the major process for quenching being α-hydrogen-atom abstraction by (UO²⁺₂)^*. Support for this comes from agreement between the isotope effects observed for quenching and for product formation. In an earlier study, the bi-exponential decay was interpreted in terms of a reversible crossing between two states, U* and X*. Analysis of the quenching data indicates that these have very similar reactivity towards alcohols. Results are also given for the decay of the intermediate hydroxyalkyl radicals in the presence of uranyl ion, and suggest that formation of the final organic product normally involves metal-ion oxidation.