Surface wax alkanes were determined in several species of Cactaceae and used as chemotaxonomic characters. Extraction of alkanes was performed with hexane and determination was carried out by GCMS on a data set including 105 species belonging to two subfamilies: Opuntioideae and Cactoideae. The Cactoideae examined were subdivided into seven tribes: Cacteae, Cereeae, Echinocereeae, Notocacteae, Pachycereeae, Rhipsalideae and Trichocereeae. The data obtained were statistically processed using multivariate methods including cluster analysis and discriminant analysis. The results obtained revealed a clear partition among species at both the subfamilial and tribal level, confirming the usefulness of wax alkanes as chemotaxonomic markers in the Cactaceae.