The major alkaloids of 12 morphologically dissimilar species of Argyrolobium Eckl. & Zeyh. have been identified. All extracts contain large quantities of anagyrine as the dominant alkaloid. Cytisine, N-methylcytisine, lupanine, sparteine, 5,6-dehydrolupanine and ammodendrine are present as minor compounds in most of the species and as major compounds only in a few of them. The data do not reflect morphological dissimilarities and the species are remarkably uniform in their major alkaloids. Our conclusions are that Argyrolobium is closely related to the genus Polhillia Stirton, that large quantities of anagyrine may be taken as a chemotaxonomic marker for Argyrolobium and that a more detailed study of alkaloids may provide valuable taxonomic evidence in a genus without any obvious morphological specializations.