The reaction of nitrous oxide (N2O) with hydroxyl (OH) is studied using high-level quantum chemistry and advanced chemical kinetics techniques. Three reaction mechanisms including a direct O-abstraction, an unusual indirect O-abstraction, and OH-addition/NO-elimination have been characterized. Reaction enthalpies calculated from first principles agree well with those of experiment. Chemical kinetics results show that the title reaction is not a candidate for short or long-time removal of N2O (with an atmospheric lifetime of at least 1 x 10(13) years) from the atmosphere but may play a minor role in high-temperature combustion where it may convert N2O pollutants to N-2.