In this issue of CHEST, Aleva et al performed a systematic review of the literature and identified another common noninfectious and noninflammatory cause of acute exacerbations of COPD: pulmonary embolism (PE). Through their search, Aleva et al discovered seven well-conducted studies, which they carefully meta-analyzed. They found that the overall prevalence of PE during acute exacerbations was 16%. Of these events, 32% (39/120) were isolated subsegmental PEs, the clinical significance of which was unknown. Of importance, they also found that the prevalence of PE varied widely depending on the severity of the exacerbation episode and patient symptoms. For instance, in patients who presented to the ED with typical features of a respiratory tract infection including fever, sore throat, or increased sputum volume or purulence, the prevalence of PE was only 3%. However, in hospitalized patients with COPD, the prevalence increased to 30% (50/172). When patients with infectious features were excluded from the analysis, the prevalence of PE in hospitalized patients was reduced to 25%. In 2009, we reported a similar prevalence of PE (20%, n = 550). The current updated systematic review added five studies to our previous meta-analysis, increasing the total number of patients with COPD to 888, which made the results more generalizable and robust. Additionally, the authors carefully evaluated the topology of PE by assessing images from CT pulmonary angiography (CTPA). They found that two-thirds of the emboli were found in sites where anticoagulant treatment may be clinically indicated. However, before accepting this notion, it is important to carefully consider the role of CTPA in detection of PE.