Aim and Background: Different studies have shown that despite the expanding number of antifungal agents, death rate caused by Aspergillus species has been increased during the recent decades due to drug-resistance occurrence, increased minimum inhibitory concentration (MIC) and cross-resistance among the isolated species. Regarding the lack of effective response to conventional treatments and antifungal susceptibility patterns of the most common isolated Aspergillus species.

 Material and method: In this study, during 9 months; 20 clinical isolates and 20 environmental strains were studied. In the next stage, drug sensitivity test was done according to the NCCLS-M38P method. A fungal suspension was made with 1-4*10⁴cfu/ml cellular range using 530nm spectrophotometer. Serial dilution of Itraconazol, Voriconazol (0.015-16mg/ml) and Caspofungin (0.007-8mg/ml) were performed and MIC was determined after 48Hr of incubation on 35^0c.

Results: In studied strains we did not find any drug resistance gene. MIC range for Aspergillus flavus in Itraconazol was determined as 0.125-2mg/ml which MIC50= 0.5 and MIC90=1mg/ml. also for vericonazol range was 0.25-2mg/ml and MIC­­­50=0.5 and MIC90=1 determined and caspofungin 0.0131-0.125mg/ml and MIC50=0.063 and MIC₅₀ = 0.063 and MIC₉₀ = 0.125.

Conclusion: According to MIC range for Itraconazol, voriconazol and caspofungin , the studied aspergillus flavus strains were drug sensitive; also, we did not find any drug resistance strain.