Chitosan plays a central role as an antifungal agent, its impact depends mainly on the concentration. In this respect, chitosan (0.4%) decreased the radial growth of Botrytis cinerea by 77.8 % under in vitro conditions. In vivo, the infection severity significantly reduced after three weeks of storage (13°C). Fruit coating by chitosan (0.4%) significantly increased fruit firmness, whereas reduced the total soluble solids, this effect was obvious with the progress of the storage time. Vitamin C content of the fruit gave fluctuated trend with the progression of storage time. The severity of the infected strawberry fruits was reduced from 100% to 49.9%  as a result of gamma irradiation (2.5KGy) whereas, in the healthy strawberry fruits, the severity was reduced from 100% to 29.1% after 3 weeks of storage period. Combination of chitosan and gamma irradiation led to a significant increment of peroxidase activity. Scanning electron microscopy of the pathogen, that was treated by chitosan, showed damages in cell structure and changes in surface morphology, the same effect was observed by gamma irradiation. The same combination was found to alter the pathogen morphology and caused damage to the cell structure. So, it is recommended using such combination for extending the shelf-life of strawberries fruits