A comparison of the cuticular hydrocarbon profiles of thirteen sympatric species of Formica ants from Finland, along with a subset of five species from the British Isles, was conducted. This permitted a comparison of the evolution of these profiles within a single genus and the stability of these profiles over large geographical and evolutionary distances. The study indicated that species-specific hydrocarbon profiles remained remarkably stable between Finland and the British Isles and were not influenced by ecological factors such as soil or vegetation types. This stability allowed candidate cuticular hydrocarbons or groups of hydrocarbons to be identified that may constitute species-specific recognition cues in these ants. In Formica, cuticular hydrocarbon composition has evolved down two distinct paths, either elevated production of Z-9-alkenes or the production of various dimethylalkanes. Evolution of hydrocarbons can be predicted for the other five Formica species for which the cuticular profiles are known. The Z-9-alkenes, dienes, and various distinctive combinations of dimethylalkanes can be used as unique species recognition cues in the Formica ants and this parallels the evolution of species-specific cuticular hydrocarbon composition in the Drosophila flies. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95, 131–140.