The aim of this study was to evaluate the effect of initial viral load and CD4 count on the response of HAART in HIV/ AIDS cases. The follow up visits and the laboratory data of 42 naive patients that HAART initiated for the first time, wereevaluated for two years retrospectively.At the beginning of therapy, median viral load was 1.3x105 (1.8x102 -7.5x106) copy/ml and median CD4 count was 169(4-1000)/mm3. In the sixth month of the therapy, negative viral load was achieved in 68 % of the cases. Negative viral loadwas detected in 74 % of patients in nonnucleozid reverse transcriptase inhibitor (NNRTI)-based therapy group and in 55 %of patients in protease inhibitor (PI) based therapy group (p=0.259). In patients with initial CD4 count <100/mm3(4-92/mm3), the median CD4 count was elevated to 126/mm3in 6th months, 201/mm3 in 12th months and regressed to 182/mm3in 24th months. In patients with initial CD4 count >100/mm3 , the median CD4 count was elevated to 362/mm3, 387/mm3and 352/mm3 respectively. There was no difference in CD4 count elevation between NNRTI ve PI based regimen groups in 6th(p=0.399) and 12th (p=0.401) months of therapy.As a result, the viral load supression was better in NNRTI based regimen with a rate of 19 % compared to PI basedregimen in the sixth month of therapy. The immunological response to therapy was better in patients with CD4 count >100/ mm3 at the beginning of treatment with the elevation of CD4 count above 350/mm3which is a boundary value.