Abstract： Background Psychological distress has been widely studied in many cardiovascular and pulmonary diseases, but the condition in acute pulmonary embolism (APE) is unknown. The purpose of this study was to investigate levels of depression and anxiety and their influencing factors in APE patients.Methods Sixty consecutive patients with APE were subjected to investigation of depression and anxiety by the Beck Depression Inventory and State-Trait Anxiety Inventory, and 60 community-based subjects were enrolled as controls.APE patients were stratified as high-risk, intermediate-risk and low-risk according to the disease severity. Scores of depression and anxiety were compared by statistical analysis using paired t tests between APE patients and controls,and by analysis of variance within the APE patients with the three risk stratification. Factors influencing depression and anxiety were evaluated.Results The mean age of the patients (38 males and 22 females) was (52+12) years. APE patients displayed higher scores of depression (P=0.04) and anxiety (P=0.001) compared with controls. Patients in the high-risk group displayed higher scores of depression (P=0.004) and anxiety (P=0.001) compared with those in the intermediate- and low-risk groups. Depression scores were highly correlated with anxiety scores (r=0.60, P ＜0.001). Both depression and anxiety inversely related to risk stratification (P ＜0.01), age (P ＜0.05), and arterial blood oxygen pressure (PaO2) (P ＜0.05).Linear regression analysis showed that PaO2 was independently inversely related to both depression (P ＜0.01) and anxiety (P ＜0.05); risk stratification and age were independently inversely related to anxiety (P ＜0.05).Conclusions Patients of APE suffered high levels of depression and anxiety, which were negatively influenced by PaO2,risk stratification and age.