Continuing chemotaxonomic studies of Australian rutaceous plants, we analyzed aerial parts of three Philotheca species (P. pachyphylla, P. scabra ssp. latifolia, P. buxifolia subspp.). Using extraction, chromatography, and spectroscopic methods, coumarins (avicennins, avicennols, eriostoic acid, protobruceols, eriobrucinols) and flavonoids (hesperidin, isobaisseoside) were isolated. Chemotaxonomic analysis confirmed Wilson's morphological classification: P. pachyphylla (section Philotheca) contains C5-prenylated coumarins, while Erionema section species (P. scabra, P. buxifolia subspp.) have C10-prenylated compounds. These findings support section distinctions in Philotheca sensu lato, with coumarins serving as consistent chemotaxonomic markers. Flavonoids showed limited taxonomic value.