Methanol extracts from 27 medicinal plant species were tested at concentrations of 0.5, 1 and 2 mg/mL for their in vivo fungicidal activities against six phytopathogenic fungi. Their efficacy varied with plant pathogen, tissue sampled and plant species. Very strong fungicidal activity was produced by extracts of Boswellia carterii, Saussurea lappa, Glycyrrhiza uralensis, Piper nigrum, Rheum coreanum, Lysimachia foenum-graecum, Evodia officinalis, Santalum album and Curcuma longa at 2 mg/mL. At 1 mg/mL, S. album, P. nigrum and L. foenum-graecum showed potent fungicidal activity against Blumeria graminis f. sp. hordei, Puccinia recondita and Magnaporthe grisea, respectively. Lysimachia foenum-graecum exhibited strong fungicidal activity against M. grisea at 0.5 mg/mL.