The serious and increasing problem of deep-seated Candida infection and the difficulties encountered in diagnosis of this entity prompted review of all well-documented cases of systemic candidiasis in a 39-month period at Stanford Medical Center. In only 19 of the 40. cases (47.5 percent) was the diagnosis suspected premortem; in 15 (37.5 percent) of these, the diagnosis was established. Thirty-three (82.5 percent) of the 40 patients died, and in 12 (39.4 percent) of them Candida infection was considered to be the primary cause of death or a major contributing factor. The seven survivors were treated either by specific chemotherapy or drainage of abscesses and empyema cavities. When the data were assessed in relation to underlying diseases and other possible predisposing factors, surgery was implicated in 50 percent of the total. In a study to define the prevalence of Candida in the saliva of patients with severe underlying illnesses receiving antibiotics or immunosuppressive therapy at the Stanford Medical Center, a significantly higher prevalence was noted in the multiple therapeutic modality group than in controls. In a review of reported data on methods for serological diagnosis of systemic candidiasis, only the precipitin and agglutinin methods appear promising.