Background and Objective: Nowadays opportunistic fungi especially C. albicans are the most common cause of life-threating infections in immunodeficiency patients. Increasing Azole-resistant strains of C. albicans are a main problem in human immunodeficiency virus-infected patients. The aim of this study was the evaluation of ERG11 gene in C. albicans Azole resistant strains that were isolated from AIDS patients with oropharyngeal candidiasis by RT-PCR method. Materials and Methods: The present experimental study was conducted at Tarbiat Modares University during the years 2009-2011. C.albicans isolates from HIV-infected patients were identified by standard procedures including germ tube formation, clamydoconidia and color of colonies on CHROM agar. At first, susceptibility of C. albicans isolates was assessed by disk diffusion agar technique. Then, overexpression of fluconazole resistance gene ERG11 using RT-PCR was compared with control samples and gene expression levels were determined by UVItec software.Results: The results of drug sensitivity for 66 C. albicans isolated from AIDS patients showed that 62.6% were susceptible, 8.6% were susceptible-dose dependent (SDD) and 28.7% were resistant. Product evaluation of RT-PCR showed that 9% of patients have increased expression of ERG11 gene resistance.Conclusion: Oral candidiasis is a frequent complication among Iranian HIV individuals. The results of this study showed the high percentage of resistant strains among samples of C. albicans. However, the use of phenotypic methods like disk diffusion agar which has lower costs together with genotypic methods like RT-PCR which provide the possibility of studying the mechanism of drug resistance and genes involved is highly recommended.