Abstract Extraction of the aerial parts of Rubus coriifolius , a medicinal plant used by the Maya communities in Southern Mexico to treat bloody diarrhoea, resulted in the isolation of seven known compounds (−)‐epicatechin, (+)‐catechin, hyperin, nigaichigoside F1, β ‐sitosterol 3‐ O ‐ β ‐ d ‐glucopyranoside, gallic acid and ellagic acid. All compounds were tested for their antiprotozoal activity against Entamoeba histolytica and Giardia lambia . Epicatechin was the main responsible for the antiprotozoal activity of the extract against both protozoa, its activity was comparable to emetine, but no exceeded that of metronidazole. Copyright © 2003 John Wiley & Sons, Ltd.