: We assessed if the increase on viral reservoir after long-term antiretroviral therapy (ART) interruption (ATI) is reversible upon ART resumption in chronic HIV-1 infected patients. Total HIV-1 DNA increased to pre-ART levels after 48 weeks of ATI to return to pre-ATI levels after 104 weeks of ART resumption. Conversely, integrated HIV-1 DNA remained elevated after ART reinitiation. These data suggest that the increase in reservoir after long-term ART discontinuation might not be reversible at midterm.