Lemon balm extracts by dry plant material of Melissa officinalis were tested against their efficacy against for different fungal species Alternaria alternata, Fusarium oxysporum, Aspergillus flavus and Beauveria bassiana. The aqueous phase of the extract was evaluated for antioxidant, antifungal and also anti-aflatoxigenic activity. A synergism evaluation was also performed concerning, the small quantity of lemon balm polar essential oil compounds extracted into the infusion and the water soluble compounds in the extract. The experiments were conducted in solid cultures and the growth inhibition was demonstrated by measuring mycelial diameter. Additionally, the effect on conidia production was also demonstrated. Lemon balm was also used for in situ test on Pistachia vera seed against Aspergillus flavus growth and aflatoxin production. Results revealed enhancement of fungal growth by lemon balm extracts however total inhibition of aflatoxins production on Pistachia vera seeds was observed, and both actions were tried to attributed to volatile and water soluble compounds identified based on GC/MS, HPLC/DAD and LC/MS, and the observed antioxidant activity. Volatile and water - soluble compounds found to be in absolute synergism in mycelium growth enhancement and the observed anti-aflatoxigenic activity addressed to the high antioxidant activity observed and synergistic action between the other water soluble phenolic compounds identified in the extract. The findings of this study underline the high biological active potential of lemon balm extracts under various screening test since for the first time full phytochemical analysis of lemon balm extracts.