Background: Due to the wide spread of Aspergillus flavus contamination on the food stuff, its complete growth inhibition is inevitable. Aloe vera has anti-microbial compounds that have significant antifungal and antibacterial activities. The aim of this study was to compare the antifungal activity of acetonic, ethanolic and aqueous extracts of Aloe vera on A. flavus growth and aflatoxin B1 production. Materials and Methods: In this study, the antifungal activity of acetonic, ethanolic, and aqueous extracts of Aloe vera was evaluated using the agar plate diffusion method. Extracts were tested at different concentrations (0, 102, 103, 104 and 105 microliters /liter). To evaluate the effect of the extract on aflatoxin B1 production, the acetonic extract of Aloe vera was used and the amount of toxin produced was measured using the HPLC method. Results: The maximum antifungal activity (100%) was observed in 105 microliters /liter of acetonic extract. The inhibition percentages of aflatoxin B1 production at 2,000 and 2 microlitters /liter concentrations in 50 ml of culture medium were 40.94% and 18.14%, respectively. Conclusion: The acetonic extract of Aloe vera can be more effective than the other solvents to prevent A. flavus growth and it can also reduce the production of aflatoxin B1by A. flavus
