The development of HIV-related disease has changed dramatically since the introduction of highly active antiretroviral therapy (HAART) into clinical practice. Since the use of protease inhibitors became widespread, a 30-50% reduction in Kaposi's sarcoma (KS) has been observed. The results of recent studies indicate that HAART may be a useful alternative both to immune response modifiers during less aggressive stages of KS disease and to systemic cytotoxic drugs in the long-term maintenance therapy of advanced KS. The impact of HAART regimens on the incidence of systemic lymphoma (NHL-HIV) remains unclear, but it can be hypothesised that patients treated with HAART may survive longer with continued B cell stimulation and dysregulation resulting in an increased incidence of lymphoma over time. The impact of HAART on survival in patients affected by NHL-HIV has recently been evaluated and a positive correlation between HAART and outcome in these patients has been found. The spectrum of cancers in patients with HIV infection may develop further since these patients survive longer with HAART and with a better control of opportunistic infections. With the increasing use of HAART, the dilemma is whether to institute or continue protease inhibitors use during chemotherapy. Based on the advances in our understanding of HIV-related disease and the availability of new antiretroviral therapies, the choice for anti-HIV agents in patients receiving chemotherapy is important.