In a review of 2,616 consecutive autopsies done at the University of Kentucky Medical Center over a 12-year period, 46 patients with complete postmortem examinations had tissue-verified candidiasis in two distinct patterns, with Candida albicans being most frequently cultured. Superficial candidiasis involving only lining surfaces was observed in 21 patients (46%). Usually, it complicated other lethal problems such as malignancy and bacterial sepsis. Nineteen of these patients (95%) had received antibiotics. No vessel invasion or deep organ involvement was evident in this group. The other pattern of candidiasis was a deep or systemic variety recognized in the remaining 25 patients (54%). It was characterized by deep parenchymal organ lesions usually involving the brain (52%), heart (48%), and kidney (80%), but any tissue seemed susceptible. Vessel invasion was seen in 8 patients (32%); intravenous lines were used in 13 (52%); and major operations were done in 16 (64%). All these patients were hospitalized for either benign or malignant conditions and were treated for bacterial sepsis with antibiotics for seven days or more. This investigation indicates that candidiasis occurs when the host's environment is altered primarily by antibiotic therapy. Candida then can colonize lining surfaces and from there could invade adjacent vessels and disseminate throughout the body.