Gray mould decay caused by the phytopathogenic fungus Botrytis cinerea is a serious problem in the world of crop production. Although the applications synthetic fungicides are currently effective for management of the disease, these methods have been prohibited in organic agriculture. Therefore, developments of alternative strategies, which better comply with organic agriculture standards, are needed. Of various strategies proposed, biological control using microbial antagonists is a promising strategy (Chan and Tian, 2005). During the past decade, many microorganisms have been reported to suppress the pathogenic activities of B. cinerea and the development of gray mould symptoms on certain crops. Among them, antagonistic yeasts are the most promised according to their basic properties, especially as they are generally recognized as safe to human. Yeasts generally do not produce allergenic spores, toxins or hazardous metabolites which posing risk to consumers (Droby et al, 1993). Furthermore, some plant associated yeasts such as epiphytic yeasts are more suitable since they can efficiently colonize the fruit surface and remain viable for long periods under various environmental conditions (Mari and Guizzardi 1998; Wilson et al., 1992). The objectives of this present study were: 1) to preliminary screen for yeasts, which possess antagonistic activities against gray mould, and 2) to evaluate the biocontrol efficacy of the yeasts isolated toward gray mould in vitro and in vivo. In addition the molecular identification for the species of the most efficacious yeast isolate was also conducted.