Background :
Mucormycosis is an acute fungal disease and opportunistic infection caused by Mucorals order which has a wide geographic distribution.
The major predisposing factors for Mucormycosis are hyperglycemia, metabolic acidosis, Supraphysrologic dosis of adrenal Corticosteroids and Leukemia.
Ferula assa- foetida is the gum resin obtained from the dried roots of this plant. It has antispasm and antimicrobial effects. It is used in the treatment of asthma and Sarcomas.Since it’s antibacterial effects was proven,but antifungal studies of this essential oil is very limited,so this study was aimed for this defect.

Methods:
In this study, we used broth microdilution method. Essential oil of the plants was extracted by means of clevenger apparatus and used on isolates in microplate wells and their MIC was calculated.

Ressult:
The number of samples was twenty five. Seven isolates didn’t grow up to the dilution of 1/8th of essential oil, ten isolates up to 1/16th and eight isolates up to 1/32nd .

Conclusion:
Because of the nephrotoxicity effects of amphotericin B, the evaluation of in vivo antifungal activity of Ferula assa-foetida essential oil (Ferula assa-foetida essential oil has not nephrotoxicity effects), drug resistance and the effect of pH and temperature on activity of this essential oil, is recommended.

Key words:
Ferula assa–foetida, Mucormycosis, Antifungal activity, Essential oil.