Antiretroviral therapy for HIV-I-infections is accompanied with the occurrence of several metabolic side effects. An often encountered complication of antiretroviral therapy is the adipose redistribution syndrome characterised by an altered distribution of body fat, and linked with protease inhibitor (PI) and nucleoside-reverse-transcriptase inhibitors (NRTIs). Some NRTIs have lactate acidosis as a side effect in rare cases (0.1%), which is accompanied by a high mortality. The far less serious side effect hyperlactaemia is more frequently observed; this is a symptomatic elevation of the lactate level without acidosis. Insulin resistance is not only ascribed to therapy-induced lipoatrophy and visceral fat accumulation, it is also directly related to the use of some PIs and NRTIs. PIs and abacavir and to a lesser extend didanosine result in a high risk of cardiovascular disease. Moreover, the prevalence of traditional cardiovascular risk factors in HIV-infected subjects is higher than that in HIV-seronegative subjects. Clinically relevant interactions exist between PIs and statins. Pravastatin seems to be accompanied with the lowest chance of interaction and is therefore recommended as cholesterol-lowering therapy. The metabolic side effects are outweighed by the favourable effect of the antiretroviral agents. Counteraction of these side effects may therefore not be at the expense of the antiretroviral therapy.