Both Hippocrates and Galen described thrush in the mouths of debilitated infants, but it has been only in the last century that systemic disease due to the opportunistic yeast of the genus Candida has been recognized. The prevalence of Candida pneumonitis has increased remarkably in the last three decades, probably because of the increased usage of broad spectrum antibiotics, immunosuppressive drugs, indwelling vascular lines, prosthetic devices, and organ transplantation. Pulmonary candidiasis can be effectively treated if recognized early in the course.