The renal function is a key-issue in HIV/HCV co-infected patients, nevertheless, it has not established so far whether HCV treatment with new direct acting agents could impact on estimated glomerular filtration rate (eGFR) variations. In the present work, we examined the real-life data on renal function that have been prospectively collected in the SIMIT compassionate-use program of ombitasvir/paritaprevir/ritonavir plus dasabuvir (OBV/PTV/r + DSV) in 144 HIV/HCV genotype 1 co-infected patients. The population was 74% male, 30.5% in CDC stage C, with median age of 52 years (48.0-56.5) and median liver stiffness of 7.8 kPa (6.7-9.2). Median baseline eGFR was 102.0 (90.8-108.1), changing to 99.8 (83.5-104.8) at the end of treatment (EoT), and 100.0 (87.3-105.6) 12 weeks after the EoT (FU12), p<0.0001. No patient had grade 3-4 increase of creatinine. At EoT 60/144 (41.7%) patients had ≥ 5% reduction in their eGFR, confirmed at FU12 in 39/60 (65.0%) cases. Longer duration of HCV infection (cut-off 12.9 years), lower HCV-RNA viral load (cut-off 1,970,160 IU/ml) and lower platelet count (cut-off 167,000 x106/L) were significantly associated with eGFR decline at logistic analysis (adjOR 2.9, 95%CI 1.0-8.8, p = 0.05; adjOR 3.5, 95%CI 1.2-10.4, p = 0.02; adjOR 2.8, 95%CI 1.1-6.8, p = 0.03, respectively). After repeating the analysis throughout a mixed model, a higher eGFR decline was highlighted in patients concomitantly treated with tenofovir (p = 0.0001), ribavirin (p = 0.0001), or integrase inhibitors (p <0.0001), with longer duration of HIV (p = 0.0002) and HCV infection (p = 0.035), lower baseline HCV RNA (p <0.0001), previous HCV treatment (p<0.0001), and older age (p<0.0001). In conclusion, our study confirms a good renal safety profile of OBV/PTV/r + DSV treatment in HIV/HCV patients, and the median decline of 2 ml/min in eGFR, albeit statistically significant, is of doubtful clinical significance. The role of aging, concomitant therapies and duration of HIV/HCV infection needs to be further investigated.