The first HIV/AIDS case has been reported in 1985 in Turkey, and since then 8238 cases have registered until June 2014 according to the records of Turkish Ministry of Health. The aim of this retrospective study was to evaluate the epidemiological data and clinical features of HIV/AIDS patients admitted to our center. A total of 255 HIV-infected patients admitted to our clinic between January 1986 and January 2013, whose data obtained from file records, were included in the study. Most of the patients were male (193/255, 75.6%) and Turkish citizens (216/255, 84.7%), with the mean age of 38.0 +/- 11.6 (age range: 19-80) years. Approximately 25.4% (46/181) were university graduates. The most frequent route of transmission was through a heterosexual intercourse (161/255, 63.1%). In our study group, there were 34 men who had sex with men, and the majority of these cases (n=26, 76.5%) were diagnosed in or after the year 2006, while 23.5% (n=8) before 2006. This difference was found statistically significant (p<0.05). The reasons that led patients for diagnosis were the presence of clinical symptoms such as diarrhea, lymphadenopathy and fever in 30.7%, and personal curiosity because of unprotected/risky sexual intercourse in 21.3% of the cases. Initial CD4(+) T lymphocyte counts could be reached for 237 cases, and the median value was calculated as 260 (range: 3-1183) cells/mm(3). Among these patients, CD4(+) T cell count was below 200/mm(3) in 40.1% (95/237), and above 500/mm(3) in 22.8% (54/237). The mean CD4(+) lymphocyte count on first admission was 240/mm(3) for those admitted before the year 2006 (n=107) and 375/mm(3) for those admitted after 2006 (n=130) (p<0.005). HIV-RNA loads could be reached for 203 cases on admission, and the median value was calculated as 67.200 copies/ml. Nearly half of the cases (91/203, 44.8%) had high viral load (>= 100.000 copies/ml). The disease could be categorized in 246 cases, 54.1% were HIV-positive and 45.9% were in AIDS stage. Patients diagnosed after 2006 had lower rate of AIDS when compared to the patients diagnosed before 2006 (33.6% vs. 60.7%, respectively; p<0.005). Two hundred patients were followed up more than three months (median: 41 months), and 138 patients (of them 79 were HIV-positive, and 59 were in AIDS stage) were still in follow up at the end of study period. Throughout the follow-up, 29 cases (29/255, 11.4%) had died. It was concluded that, the surveillance of data from HIV/AIDS patients would be beneficial to determine and predict the complications of the disease.