Little is known about the chemistry of P. atlantica, P. khinjuk and P. lentiscus. The flavonoids of four Pistacia species (P. atlantica, P. chinensis, P. khinjuk, P. lentiscus) in Egypt were studied. Fresh material was extracted with 70% ethyl alcohol (3 times), concentrated and separated on polyamide columns, and flavonoid glycoside fractions were purified by paper chromatography and Sephadex LH-20 columns. Standard identification methods including complete and partial acid hydrolysis, hydrogen peroxide oxidation, enzymatic hydrolysis, co-chromatography, UV spectrophotometry and nuclear magnetic resonance measurements were used. Nine flavonoid glycosides were isolated from the aerial parts of the four species and identified. Chemotaxonomic analysis showed that P. khinjuk, as the only evergreen member of the genus, was unique in its flavonoid composition with three myricetin glycosides as major components, while the other three species contained quercetin 3-glucoside as their major glycoside.