abstract the chemical composition of craft and industrial niaouli (melaleuca quinquenervia) leaf essential oils from madagascar has been investigated over ten years. samples (159) which are representative of this country correspond each year to 1.5-2 tons essential oil production. among the various components identified by gc/ms, twenty-one were used for statistical analyses, the major components were - pinene (0.1-17%), limonene (0.0-12%), 1,8- cineole (0.0-71%), - terpineol (0.0-12%), (e)-nerolidol (0.0-95%) and viridiflorol (0.1-36%). niaouli essential oils from madagascar were classified into three chemotypes using principal component analysis (pca): a cineole chemotype (49-62%), a viridiflorol chemotype (21-36%) and an (e)-nerolidol chemotype (56-95%). the 1,8-cineole chemotype is widespread, representing 92% of the samples investigated if the leaf collection is done at random. the chemotype choice for production is possible using tree selection by leaf olfactory selection before leaf harvesting for essential oil production