To review the estimated incidence of cytomegalovirus (CMV) disease, its diagnosis and currently accepted treatments and those under investigation. CMV DISEASE IN PATIENTS WITH HIV INFECTION: The most frequently occurring manifestation of CMV disease is retinitis, occurring in approximately 20-40% of patients. Oesophagitis and generalized infection are also common.At present, diagnosis relies on specific histopathology as serology is unreliable and CMV culture lacks sensitivity and specificity. Assessment of the presence of CMV-specific proteins and polymerase chain reaction assays of CMV DNA may prove useful.Intravenous ganciclovir and foscarnet are equally effective for the treatment of CMV disease, but ganciclovir is generally regarded as the primary treatment option due to its relative ease of administration. Combination therapy with these agents is also effective in the treatment of CMV retinitis. As well as patients with sight-threatening retinitis, patients with peripheral retinitis benefit from immediate treatment. Local treatment with a ganciclovir implant or intravitreal injection is effective, but does not provide protection against ocular complications, infection of the contralateral eye and extraocular disease. Oral ganciclovir is virtually as effective as intravenous administration for secondary prophylaxis versus maintenance treatment for CMV retinitis with the advantage of a more favourable adverse-effect profile.Intravenous ganciclovir and foscarnet are equally effective in the treatment of CMV disease. Oral ganciclovir is effective in secondary prophylaxis and provides a welcome alternative to intravenous maintenance treatment.