The prognostic role of pleural and pericardial effusion in patients with acute pulmonary embolism (PE) is still unclear with a trend for worse clinical outcome. The aim of the present study was to demonstrate the prognostic role of pleural and pericardial effusion in patients with acute PE in a large multicentre setting. The investigated patient sampled was retrospectively comprised of 1082 patients (494 female, 45.7%) with a mean age of 63.8 years ± 15.8. In every case, contrast enhanced computed tomography (CT) pulmonalis angiography was analyzed to diagnose and quantify the pleural and pericardial effusion. The 30-day mortality was the primary endpoint of this study. A total of 127 patients (11.7%) died within the 30-day observation period. Pleural effusion was identified in 438 patients (40.5%) and pericardial effusion was identified in 196 patients (18.1%). The presence of pleural effusion was associated with 30-day mortality, HR = 2.78 (95%CI1.89-4.0), p < 0.001 (univariable analysis), and HR = 2.52 (95%CI1.69-3.76), p < 0.001 (multivariable analysis). The pleural effusion width and density were not associated with 30-day mortality. The presence of pericardial effusion was not associated with 30-day mortality in multivariable analysis, HR = 1.28 (95%CI 0.80-2.03), p = 0.29. Pleural effusion is a common finding in patients with acute pulmonary embolism, occurring in 40.5% of cases, and is a prognostic imaging finding associated with 30-day mortality. The presence of pleural effusion alone, regardless of volume or density, has been shown to be prognostic and should be included in CT reports. The prognostic role of pericardial effusion is limited.