Hypoglycaemic effects of Salsola kali, S. soda, and S. oppositifolia (Chenopodiaceae) aerial parts were examined using in vitro assay based on the inhibition of a-amylase. The S. kali ethyl acetate fraction was the most active with a C1050 value 0.022 mg/ml. Through bioassay-guided fractionation processes two flavonol glycosides, isorhamnetin-3-O-glucoside and isorhamnetin-3-O-rutinoside, were isolated by silica gel column chromatography and characterized by spectroscopic methods. Isorhamnetin-3-O-rutinoside showed an interesting activity (IC50 0.129 mM).