Acute HIV infection presents as a mononucleosis-like disease with fever, lymphadenopathy, myalgias, rash and headache. Other symptoms are occurring at lower frequency. Since acute HIV infection is associated with high viral loads it is important to diagnose patients with this entity, in order to prevent transmission. It is still controversial whether very early therapy during acute seroconversion is beneficial on the long-run. Small studies may indicate that early therapy which is followed by a stop of antiretroviral therapy after one to two years may be followed by a better control of viremia.