Improved understanding of cholesterol levels in HIV and HCV-infected persons in Argentina will guide optimal antiretroviral therapy. We conducted a cross-sectional study in Argentina to describe associations between HIV, Hepatitis C and cholesterol. Of 202 participants, 21 were HIV-infected, 15 HCV-infected, 46 were HIV/HCV co-infected and 120 were HIV/HCV uninfected. HIV/HCV uninfected participants had the highest total cholesterol (TC) and LDL levels. Multivariate modeling revealed that HIV/HCV co-infected patients had the lowest TC levels (−28.7 mg/dl, p<0.001) compared to the HIV/HCV uninfected reference group. HCV and HIV/HCV co-infection were associated with lower LDL levels (−21.4 mg/dL, p=0.001 and −20.3 mg/dL, p<0.0001, respectively). HIV and HIV/HCV co-infection, but not HCV alone, were associated with lower HDL levels (−9.1 mg/dL, p=0.0008 and −6.8 mg/dl, p=0.0006 respectively). Further study is needed to examine if the more favorable lipid profile observed in HIV/HCV co-infected persons is associated with a reduction in cardiovascular risk.