The diagnosis of the CPFE syndrome is established after HRCT imaging, sometimes in conjunction with pathology. A consensus definition of CPFE syndrome does not currently exist. In the broadest sense, this term should include all patients with coexistent emphysema and pulmonary fibrosis pathology, although current methods of detection, such as HRCT scanning, likely allow identification of a portion of this larger group. The combination of emphysema and pulmonary fibrosis detectable on HRCT scan initially was reported in the setting of apparent idiopathic pulmonary fibrosis (IPF),4 and in this setting, emphysema is a relatively common finding on CT scan (Table 1). However, although a pattern of usual interstitial pneumonia/IPF appears to be the most common imaging or pathologic findings in the setting of CPFE, other patterns of fibrotic interstitial lung disease have been reported in conjunction with emphysema,7,9 and the presence of IPF, therefore, is not necessary for the diagnosis of CPFE. Most reported cases of CPFE (Table 2) seem to share certain characteristics, including male sex, a history of cigarette smoking, relatively preserved spirometric values, and decreased diffusing capacity of lung for carbon monoxide (Dlco). These common factors have led to the description of a CPFE syndrome,6 which denotes the subgroup of patients with coexistent pulmonary fibrosis and emphysema who present with dyspnea, often in the setting of a history of smoking; who have the characteristic physiologic abnormalities; and who frequently also have pulmonary hypertension. Classification of this group of patients under the CPFE syndrome label is important because as discussed later, these patients have a different natural history, complications, and mortality than those with pulmonary fibrosis or emphysema alone. What remains unclear is what extent of emphysema and fibrosis is needed to distinguish the patient with CPFE from patients with predominant emphysema or predominant fibrosis.