Cholesterol embolization is a puzzling event that may be increasingly iatrogenic in origin. Diagnosis is difficult and requires a high index of suspicion, an appropriate clinical picture, and usually, confirmation by biopsy. Certain laboratory abnormalities may be helpful; the elevated sedimentation rate and relative eosinophilia found in our patients concurs with other cases reported in the literature. Prognosis is related to the extent of systemic involvement, but renal disease is particularly threatening and gangrene and infection can be lethal. Multiple therapeutic regimens have been generally unsuccessful in altering the course of the disease process. The most significant impact on the disease can be made by its prevention. Cholesterol emboli occur spontaneously, but also after invasive aortic procedures such as diagnostic angiography or cardiovascular surgery. In addition, cardiac catheterization and percutaneous transluminal coronary angioplasty have the potential for arterial trauma and consequent cholesterol embolization. Although the apparent increasing numbers of cholesterol emboli may be a reflection of the increased use of arterial invasive procedures, they are being performed on an older, more severely ill population, with other risk factors for the development of embolic phenomena, i.e., age, smoking history, diabetes mellitus, hypertension, and peripheral vascular disease. Our observed cases and review of the literature do not furnish information concerning the comparative incidences of embolization as related to the suggested etiologies. Careful documentation of the clinical situation preceding the event, the type of procedure, the site of arterial entry, and the duration, difficulty, and extent of the intravascular invasion (i.e., above or below the left subclavian artery) are necessary for this purpose. Such data should help to develop guidelines for patient and procedure selection in order to minimize the possibility of cholesterol embolization.