Abstract The leaf oils of the four species which comprise the Melaleuca minutifolia group have been examined by GC and GC/MS. The leaf oils of M. minutifolia contained a mixture of both mono- and sesquiterpenes, with α-pinene (16â20%) bring the principal monoterpene. The main sesquiterpenes present in the oil were aromadendrene (3â11%), bicyclogermacrene (5â10%) and γ-, α- and β-eudesmol (7â11%, 5â7% and 8â12% respectively). Melaleuca monantha produced an oil which was much richer in α-pinene, 20â54% from one site and 66% from a second site accompanied by lesser, though still significant amounts of β-pinene (14â30% from one site and 2â9% from the second site). Melaleuca sylvana produced an oil in which α-pinene (26â62%) was the principal component. The main sesquiterpenes were β-caryophyllene (5â13%), bicyclogermacrene (3â11%). The leaf oil M. uxorum contained α-pinene (5â17%), bicyclogermacrene (6â13%), globulol (8â14%), spathulenol (6â14%) and viridiflorol (3â10%) as the main components. PCA analysis supports the taxonomic distinctness of the four species.