Antiviral chemotherapy has come of age. Several compounds, i.e. amantadine, rimantadine, idoxuridine, trifluridine, vidarabine, acyclovir, ribavirin and azidothymidine, have been licensed for clinical use and other promising compounds may follow soon. The search for new antiviral agents has been boosted by the advent of AIDS, but the activity spectrum of the newly developed antivirals not only spans retroviruses but also various other virus infections, i.e. herpes-, adeno-, pox- and rhinovirus infections. Clinical trials have been started with a variety of these new compounds and the prospects for an effective chemotherapy of several viral diseases certainly look bright.