During the past two decades, there has been a significant increase in the prevalence of fungal infections caused by Candida species. Oral candidiasis is a common opportunistic infection of the oral cavity caused by yeast fungi of the genus Candida on the mucous membranes of the mouth. To isolate and determine the incidence rate of oral Candida species in periodentitis and gingivitis patients referred to school of dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran, this study was carried out in 172 patients with periodentitis and gingivitis aged 11 to 72 years. Swabs samples were taken from salivary secretion, the palate mucosa and dentine carious lesions and were cultured directly on Sabouraud dextrose agar medium. Isolated yeasts were identified by CHROMagar Candida, germ tube test and Clamidoconidia formation (corn meal agar plus Tween 80 medium). Results showed the prevalence of Candida albicans (n = 120, 75%), Candida glabrata (n = 20, 12.5%), Cadida tropicalis (n = 10, 6.5%), Candida dubliniensis (n = 6, 4.0%) and Cadida krusei (n = 3, 2.0%). In this investigation, germ tube-test and chlamydospore formation were positive in the isolates that produced dark-green colonies and were considered as C. dubliniensis and light-green colonies were identified as C. albicans. CHROMagar Candida is a satisfactory isolation medium for oral and dental specimens. It is a satisfactory method for correct and rapid identification of common yeast species and easy recognition of mixed cultures in clinical samples.