Dermatophytoses are infections of keratinized tissues, that is, skin, hair, and nails caused by a group of specialized fungi (dermatophytes). The dermatophytes produce infections with mild to severe symptoms depending on the immunological response of the host. From September 2002 to September 2003, one hundred and one patients included in this study. They were selected from the outpatient dermatological clinic of Al-Kadymia Teaching Hospital. The study included forty males and sixty-one females, their age range from 1 year to seventy years old. Both epidemiological and immunological studies were done, which focused on patients with dermatophytoses and with a comparison between the acute and chronic type of dermatophytoses The clinical examination revealed 36 cases with onychomycosis, 29 cases Tinea corporis, 17 cases Tinea capitis, 15 cases Tinea pedis, cases for both of Tinea manuum and Tinea cruris, and only 2 cases with Tinea barbae. Direct microscopic examination by potassium hydroxide preparation was positive in 71 cases, while the culture was positive in 73 cases, from the 73 positive culture results, 23 cases with the yeast Candida alblcans, 20 cases with Trichophyton rubrum, 11 cases Microsporum canis, 5 cases of both of M.gypseum and T.mentagrophytes, while only 2 cases of T.tonsurans. Concerning age of patients included in the study, the age group (1-19) years old showed the highest incidence of fungal infections. Incidence of the disease was highest among females compared to males (1.5:1). Results of our study showed that non of the risk factor, i.e.; blood group, atopic status of the patients, and diabetes mellitus, had direct effect in dermatophytoses. Two main lines of work were used in the immunological aspect of this study these include:(1) Peripheral blood lymphocytes (PBL) CD markering were applied on the frozen and fixed isolated PBL slides of 17 patients with dermatophytoses and 10 apparently healthy people used as control subjects. Direct immunoflourescence test was used to detect CD lie, CDllb, CD45RO, and CD22 monoclonal antibodies. While the CD3+, CD4+, and CD8+ T-lymphocytes subsets were detected by indirect immunostaining test for the same processed slides. (2) In vitro mononuclear cells mitogenic stimulation technique by using microculture tetrazolium assay (MTT) test, was applied on the freshly isolated PBL from 15 patients with dermatophytoses and 15 apparently healthy control subjects. The mitogen was Concavalin-A (Con-A) as a control positive, to determine the cell-mediated immunity (CMI) level. in dermatophytic patients in comparison with the healthy control Subjects, focusing on the differences in the CMI level between acute and chronic dermatophytoses. The investigation for the pronounced depression of in vitro blastogenesis of PBL was done by using the following: Dermatophyte-specific antigen, prepared in our laboratory and known as heat-killed soluble antigen (sAg), for the detection of the specific inhibition. Autologous serum (AS) to detect the presence or absence of specific and/or non-specific inhibition that might be present in patient's serum. The most important findings of this study were as following: Low level of circulating CD3+ and CD4+ cell populations in dermatophytic patients in comparison to healthy control subjects, which was manifested more among chronically infected patients than acutely infected patients. Indicated by the significant differences (P<0.05) between patients and controls and between chronically and acutely infected patients. CD4/CD8 ratio in dermatophytic patients was much lower than the ratio in control subjects, mainly due to the increase in CD8+ cells population among dermatophytic patients. The low CD4/CD8 ratio and the low CMI level in dermatophytic patients indicated immune suppression in these patients. •Non-significant differences (P>0.05) in the level of CD45RO+, CD22+, CD1 lc+ cell populations between patients and controls group, and between acutely and chronically infected patients was obvious. • High level of CD1 Ib expression in patients than in controls group, and in chronically infected patients than in acutely infected patients was observed. Pronounced depression of in vitro blastogenesis by MTT assay, of the PEL of both patients and controls group, was mediated by the prepared dermatophyte-specific antigen (sAg). Absence of the specific and/or non-specific serum inhibitory factors in the sera of patients with dermatophytoses was clear.