Rate constants for the reactions of OH radicals with CH₂=CHNO₂, CH₂=CH-CH₂NO₂ and c-C₆H₉NO₂ have been determined at 298 ± 2 K and a total pressure of 1 atm. Rate data for the reaction of OH radicals with CH₂=CH₂, CH₂=CH-CH₃ and c-C₆H₁₀ were also obtained for comparison purposes. The OH rate data for all the compounds except c-C₆H₉NO₂ were obtained using the absolute technique of pulse radiolysis combined with kinetic UV spectroscopy. Water-argon mixtures were irradiated and the OH kinetics recorded by following the transient light absorption at 309 nm. The rate constant for the OH + c-C₆H₉NO₂ reaction was derived using a conventional photolytic relative-rate method. The results are discussed in terms of structure-reactivity relationships.