Three cases of oesophageal candidiasis in association with primary HIV infection are described. In each case the candidiasis was associated with a decreased number of circulating CD4+ cells and responded well to treatment with ketoconazole. Clinicians should be aware that severe opportunistic infections may develop during this stage of infection, presumably as a result of transient immunodeficiency. We argue that the definition of primary HIV infection should be extended to include severe opportunistic infections and neurologic presentations.