The use of combinations of antiretroviral drugs can profoundly suppress HIV replication for prolonged periods and has substantially decreased AIDS-related morbidity and mortality. The optimal use of antiretroviral drugs remains a rapidly evolving field and numerous obstacles need to be addressed. Many regimens are associated with substantial toxicity, large pill burdens and high cost. In addition, it has become clear that currently available regimens cannot completely suppress HIV replication. Nevertheless, the goal of antiretroviral therapy remains the suppression of plasma viremia as much as possible for as long as possible. Additional goals of therapy include restoration and preservation of immune function, minimization of toxicity, to prevent the disruption of lifestyle and the emergence of drug-resistance virus strains. In some patients a sustained elevations in CD4 cell counts occur despite incomplete viral suppression during HAART. The optimal therapeutic approach in these patients is still unclear. If, as it is generally assumed, viral load determinations reflect ongoing viral replication, then the evolution of drug resistance might be expected. Thus, to prevent the emergence of multidrug resistance, also in these patients a change to a salvage therapy is a viable option.