Pyricularia oryzae, the causal agent of rice blast disease, is a serious threat to rice. it reduces the yield and quality of rice. agrofungicide used to control rice blast is harming the environment and human health. safer alternative is needed. this study aimed to investigate the antifungal activity of zinc oxide nanoparticles (ZnO NPs) against P. oryzae of sarawak, and its phytotoxicity towards sarawak rice. solvothermal sysnthesis method was used to synthesize two sizes of ZnO NPs (~20 nm and ~40 nm). ZnO NPs showed inhibition effect on P. oryzae tested and the effect was isolate dependent. the effect increased along with the concentration increment of ZnO NPs. ZnO NPs were found not affecting the seed germination rate, but on the shoot and root development. the effect varies at different concentration treatments of ZnO NPs. landrace/genotype dependent phytotoxicity effect of ZnO NPs was observed.