Systemic fungal infection are increasing in number throughout the developed world. Numerous studies have identified common risk factors for patients developing fungal infection. The most common recognised factors are: colonization, broad-spectrum antibiotics, indwelling central catheter, total parenteral nutrition, immunosuppression, burns, and general measure of severity of illness. Given the benefit of an early therapy, an accurate and prompt diagnosis is crucial. Because the current techniques of securing a diagnosis of fungal infections are imperfect, diagnosis of these infection is often made on clinical grounds. It is thus important for the clinician to know and identify the risk factors to have a high index of suspicion in critically ill patients.