From the overground parts of an endemic Sideritis species, S. stricta, 4 diterpenes, sideridiol (1), isosidol (2), isolinearol (3), and linearol (4); 2 flavonoid glycosides, isoscutellarein 7-O-[6"'-O-acetyl-O-Dallopyranosyl-(1 -> 2)]-beta-D-glucopyranoside (5), and isoscutellarein 7-O-[6"'-O-acetyl-beta-D-allopyranosyl-(1 -> 2)]-6"-O-acetyl-beta-D-glucopyranoside (6); a methoxyflavone, xanthomicrol (7); and a phenylethanoid glycoside, verbascoside (=acteoside) (8) were isolated. The structures of the isolated compounds were established based on spectroscopic evidence (UV, IR, ID- and 2D-NMR, MS).