Brachychiton australis (Schott and Endl.) A. Terrac and Brachychiton discolor F.Muell. (Malvaceae) are widely grown in Egypt and observed as important biological species. Chemical studies of the 70% methanol/water extracts of the leafy branches of both species were carried out based on isolation and characterization of phytochemical constituents. Chromatographic and spectroscopic methods of both extracts revealed the isolation and identification of twelve phenolics. Eight isolated flavonoids (vicenin, schaftoside, violanthin, isoviolanthin, luteolin 7-O-β-glucuronide, apigenin 7-O-β-glucuronide, apigenin 7-O-β-glucopyranoside, and acacetin) were characterized for B. australis while three phenolic acid derivatives (trans-p-coumaric acid, trans-p-coumaric acid-O-glucoside, chlorogenic acid) and one flavonol glycoside (rutin) are considered for B. discolor. Except rutin, all compounds were reported for the first time in each species. The LC-ESI-MS assay of both extracts revealed the annotation of additional nineteen compounds including eight flavonoids, five phenolic acids, two organic acids, two fatty acids, one saccharide, and one amino acid. The most of characterized compounds could be useful for further pharmaceutical applications. Moreover, this study presents a step forward for approaching chemosystematic revision of the examined species within the genus Brachychiton