Background and Objective: Human immunodeficiency virus (HIV)infected people are at higher risk of opportunistic infections due to immunodeficiency. The current study aimed to evaluate the different levels of CD4 in HIV-infected patients and its relationship with clinical and paraclinical manifestations of the patients. Materials and Methods: This cross-sectional study was conducted on 94 HIV-infected patients referred to the Counseling Centers for Behavioral Diseases and Sina Hospital in Hamadan, from 2014 to 2015. At the commencement of the study, written consent was obtained from the participants. Thereafter, demographic data, history of underlying diseases, symptoms and clinical syndromes, medical history, and serum CD4 levels were evaluated by flow cytometric recorded in the questionnaire and data were analyzed in SPSS software(version 16). Results: Out of 66 HIV-positive patients, 70.2% (n=38) were male and the mean age of the patients was 40.06±10. 04 years. In terms of classification of the clinical stage of the disease, the patinets in the first, second, and third stages were reported as 11 (11.7%), 36 (38.3%) and 34 (36.2%), respectively. The mean serum CD4 count of the patients at the beginning of antiretroviral therapy was measured at 284.241±284 and 377.19±271.41 cells /μl, respectively. The difference in the mean of serum CD4 count before and after antiretroviral therapy was revealed to be statistically significant (P=0.001). The most common clinical symptoms observed included cough and sputum (29.9%), oral aphthous ulcer (12.7%), weight loss (11.7%), and fever (7.4%). Based on the results of the study, there was a significant difference between the mean of platelet count, hemoglobin and alkaline phosphatase at different levels of CD4 (P<0.05). Conclusion:According to the results of the present study, serum CD4 levels rise with the initiation of antiretroviral therapy in HIV infected patients; therefore, early antiretroviral therapy in HIV-infected patients with any serum CD4 level is of paramount importance.