Abstract The phytochemical investigation on Tanacetum sinaicum (Fresen.) Delile ex Bremer & Humphries led to the isolation of eight flavonoid aglycones (apigenin 1 , acacetin 2 , luteolin 3 , chrysoeriol 4 , cirsilineol 5 , jaceidin 6 , chrysosplenetin 7 and vitexicarpin; casticin 8 ), four flavonoid glycosides (apigenin 7- O -β-glucopyranoside 9 , apigenin 7- O -β-glucuronide 10 , luteolin 7- O -β-glucopyranoside 11 and luteolin 7- O -β-glucuronide 12 ) and three phenolics (4-hydroxy-3-methoxy benzoic acid 13 , 3,4-dimethoxy benzoic acid 14 and 4-hydroxy acetophenone 15 ). Their structures were determined by chemical and spectroscopic analysis. Among them, compounds 1–3, 9, 11, 13 and 14 were reported for the first time from T. sinaicum . The chemotaxonomic significance of the isolated flavonoids was also summarized.