The incidence, characteristics of pleural effusions due to pulmonary thromboembolism (PTE) have been reported previously. However, the impact of pleural effusions on the prognosis of acute PTE patients and the involved influencing factors remain unclear. A total of 518 consecutive PTE patients were enrolled in Beijing Chao-Yang Hospital from January 2009 to April 2014. The diagnosis was confirmed with Spiral computer tomography pulmonary angiography or/and high-probability ventilation and perfusion scans. All patients finished one-year clinical follow-up. Among 518 patients with acute PTE, pleural effusions were found in 120 patients (23.2 %). No strictly tight association between side of pleural effusions and location of thrombus was observed. The diagnosis time between patients of PTE with pleural effusions and without pleural effusions had no statistically significant difference. During the 3-month follow-up, the all-cause mortality of PTE patients with pleural effusions was significantly higher than those without pleural effusions [10/120 (8.3 %) vs. 8/398 (2.0 %)]. During the 1-year follow-up, analysis of survival also showed that all-cause mortality was significantly higher in PTE patients with pleural effusions than those without pleural effusions. In both univariate Cox-regression analysis [P < 0.001, HR 3.044, 95 % CI (1.647, 5.625)] and multivariate Cox-regression analysis [P < 0.05, HR 2.040, 95 % CI (1.038, 4.009)] pleural effusions showed to be risk factor of poor prognosis. Pleural effusions in patients with acute PTE were significantly correlated with higher mortality. Pleural effusions in acute PTE patients might be used as a predictive parameter for prognosis.