Single nucleotide polymorphisms (SNPs) rs12979860 and rs8099917 near the interleukin 28B gene are predictors of virological response (SVR) to IFN-based therapy for monoinfected chronic hepatitis C patients. We retrospectively evaluated the impact of IL28B SNPs and other factors on SVR in a cohort of 102 HIV-1/HCV-coinfected patients treated with pegylated interferon-? (peg-INF?) and ribavirin. Data on baseline features and virological response at different time-points were collected. Overall, 89/102 patients (87%) were males, 44 (43%) of whom infected with HCV genotype 1; SVR was achieved by 50 patients (49%). A univariate logistic regression analysis demonstrated that rs129679860 SNP genotype CC (p<0.034), rs8099917 SNP genotype TT (p<0.01), HCV genotype 2 or 3 (p<0.0001), low HCV viral load (p<0.028) and RVR (rapid virological response) (p<0.0001) were associated with a higher likelihood of SVR. Multivariate analysis confirmed only RVR and HCV genotype as independent predictors of SVR. In a real life setting, the importance of RVR and IL28B SNPs was confirmed as predictive of SVR to identify patients with a higher likelihood of SVR to Peg-INF?+RBV, and also to designate a deferred therapy for patients with a low likelihood of SVR for whom it is preferable to wait for more successful options.