HIV-infected patients are at increased cardiovascular risk. Although several studies have analyzed the hemorheological profile in these patients, studies dealing with erythrocyte deformability are scarce. Moreover, studies have been performed in HIV patients on antiretroviral treatment which may influence this rheological parameter. We analyzed erythrocyte deformability (Elongation Index) at 12, 30 and 60 Pa by means of the Rheodyn SSD in 34 naïve HIV-infected patients (22 males and 12 females) and 34 HIV negative control subjects (24 males and 10 females). Erythrocyte indices (MCV, MCH, MCHC), reticulocytes, plasma lipids, iron, folic acid, vitamin B12 and hepatic enzymes were also determined. When compared with controls, naïve HIV-infected patients showed lower total cholesterol, iron, bilirubin and folic acid (p = 0.009, p = 0.003, p = 0.004, p = 0.004, respectively) and higher triglycerides (TG), aspartate aminotransferase (AST) and gamma glutamyl transferase (γGt) levels (p = 0.017, p = 0.042, p = 0.004, respectively). In the multivariate regression analysis, MCV, γGt and triglycerides were independent predictors of EI60. Neither erythrocyte indices nor reticulocyte count showed differences (p > 0.05). No differences in the Elongation Index at any of the shear stresses tested (12, 30, 60 Pa) were found (p > 0.05). The results of the present study indicate that naïve HIV-infected patients not on antiretroviral treatment do not present decreased erythrocyte deformability when compared with HIV negative control subjects.