The essential oils of a series of Leptospermum species belonging to Group 8 of our classi®cation have been examined. L. micromyrtus Miq., L. minutifolium C.T. White, one chemotype of L. myrtifolium Sieber ex DC., L. rupestre Hook. f., and L. sejunctum Joy Thomps. produced oils rich in sesquiterpenes, a-, b- and g-eudesmol being the most signi®cant compounds. L. myrtifolium existed in two chemotypes, the second of which contained (E,Z)-farnesal (5.8%), (E,E)-farnesal (12.9%), 2,3-dihydro-(E)-farnesol (10.3%) and (E,E)-farnesol (26.5%) as its principal components. One chemotype of L. novae-angliae Joy Thomps. contained (E)-nerolidol (50%) as a major component, while L. rupicola Joy Thomps. contained a- and b-pinene as principal components (totalling approximately 50%). L. continentale Joy Thomps., L. gregarium Joy Thomps., L. juniperinum Sm., a second chemotype of L. novae-angliae, L. obovatum Sweet, both varieties of L. scoparium J. R. Forst & G. Forst. and L. squarrosum Gaertn. contained a mixture of mono- and sesquiterpenes, usually with the latter predominating.