Several studies have reported improvement in lipids after antiretroviral therapy switches to tenofovir disoproxil fumarate (TDF)-containing regimens. We assessed lipid-lowering effects of TDF by adding it to a stable antiretroviral therapy regimen in this double-blind, placebo-controlled crossover study. We demonstrated that nonhigh-density lipoprotein cholesterol, low-density lipoprotein cholestrol, and total cholestrol improved significantly over TDF vs. placebo treatment in HIV-infected individuals with dyslipidemia. Adding TDF to stable, virologically suppressive antiretroviral therapy regimens improved lipid parameters, supporting a lipid-lowering effect of TDF.