The volatile composition of Klainedoxa gabonensis Pierre ex Engl., Brachystegia nigerica Hoyle et A. Jones and Acalypha segetalis Muell Arg., has been studied. The essential oils were obtained by hydrodistillation in a modified Clevenger-type apparatus while the analyses were performed by GC and GC/MS. The main constituents of K. gabonensis oils were geranyl acetone (13.8%), β-bourbonene (11.1%) and (?)-α-ionone (10.5%) from the leaves; linalool (17.4%), 1, 8-cineole (9.9%) and 1-octen-3-ol (8.0%) from the stem bark, with 1, 2, 3-trimethylbenzene (9.8%), 1-ethyl-2-methyl benzene (9.1%), pentyl benzene(9.1%) and methyl salicylate (9.1%) occurring in higher proportions in the root oil. The leaf oil of B. nigerica was dominated by α-pinene (17.7%), β-selinene (12.5%) and α-gurjunene (8.8%). The main compounds identified in the oil of A. segetalis were α-pinene (29.8%), 1, 8-cineole (16.2%), (?)-phytol (11.8%) and δ-3-carene (9.8%). The present investigation may represent the first of its kind on the characterization of the volatile constituents of the studied plant samples. © 2008, Taylor &amp; Francis Group, LLC. All rights reserved.