Plant diseases caused by fungi are one of significant destructive pathogens to economiccrops of Thailand and worldwide. The most common plant pathogenic fungi infectedcrops in Thailand are Pyricularia oryzae Cavara., Rhizoctonia solani (J.G Kuhn),Phytophthora palmivora Butler., Sclerotium rolfsii Sacc., and Colletotrichum

gloeosporioides Penz. and Sacc. Control of these pathogens is by using syntheticfungicides which are expensive and harmful to environment. This study aims at investigating the efficacy of the extract of five plants - Hydnocarpus anthelminthicus Pierre ex Laness., Crateva magna (Lour.) DC., Caesalpinia sappan L., Xanthophyllum lanceatum J. J. Sm., and Carallia brachiata (Lour.) Merr. to inhibit the growth of five

plant pathogenic fungi in in vitro conditions at various concentrations. At the 10,000 ppm concentration H. anthelminthicus fruit extracts exhibited reduction in antifungal potential to growth inhibition, and recorded 100 % growth inhibition against P. oryzae, P. palmivora and R. solani followed by S. rolfsii at 96.33 % when compared with water control. X. lanceatum fruit extract that logged excellent inhibitory activity against P.

oryzae. Antifungal potential was observed with the extract of C. sappan, which recorded the best inhibitory activity against P. palmivora and S. rolfsii at 88.89 and 78.89 % respectively. Results from this study demonstrated that the ability of some plant extracts viz., H. anthelminthicus, X. lancelatum and C. sappan could be used to control the growth of plant pathogenic fungi and may be applied as an alternative method to reduce fungicide.