Seeds contaminated with pathogens are the primary inoculum for plant diseases in many food crops. Conventional treatments for seedborne diseases use hot water, chlorine or fungicide applications. A novel seed treatment method based on non-thermal plasma generated by an air dielectric barrier discharge (DBD) device was evaluated in this study as an alternative to these conventional treatments. The non-thermal plasma at atmospheric pressure and room temperature consisted of partially-ionized gases that are chemically reactive. The antimicrobial activity of non-thermal plasma was evaluated against an important seedborne pathogen, Gibberella fujikuroi, that causes bakanae disease in rice. Non-thermal plasma treatments effectively inhibited the growth of G. fujikuroi on nutrient growth medium and reduced the number of fungal colony forming units (CFU) on the rice seed surface by > 92% after 120 s exposure. Effective exposure times to 50% (ET 50 ) and 90% (ET 90 ) control of G. fujikuroi CFU on the seed surface were 9 and 76 s, respectively. Ten minutes of non-thermal plasma treatment on seeds infested with G. fujikuroi significantly reduced disease development. No adverse effects were detected on the seedling emergence and height when non-infested seeds were treated with non-thermal plasma for up to 20 min. The treated seeds germinated and grew similarly compared with non-treated non-infested seeds. This study indicates that non-thermal plasma had antifungal activity and showed potential as an effective disinfection technique to reduce the contamination of seedborne fungal pathogens from seed surfaces without compromising seed health © Crop Science Society of America.