BACKGROUND: Ultrasound-assisted catheter-directed thrombolysis (USAT) is a treatment option for patients with intermediate-high- or high-risk pulmonary embolism (PE). This study aimed to describe the use of USAT and its clinical outcomes. METHODS: In this single-center retrospective cohort study, all USAT procedures performed between May 2019 and June 2022 were included. Data were collected from electronic health records. The primary outcome was reduction in right vs. left ventricular diameter (RV/LV ratio). Secondary outcomes were in-hospital mortality and bleeding. RESULTS: A total of 107 patients underwent USAT for PE. The median age was 64 (IQR 53-75) years and 59% were male. Technical success of USAT was achieved in 105 (98%) cases. In 32 cases data on RV/LV ratio changes were available. RV/LV ratio decreased by 0.29 ± 0.19 from 1.19 (1.02-1.35) to 0.89 (0.78-1.00). 12 (11%) patients had a fatal outcome. Bleeding complications were observed in 28 (26%) patients, including 14 (13%) major bleedings and 0 (0%) fatal. Both, death and bleeding rates were significantly higher in high-risk patients. CONCLUSION: We observed a high technical success of USAT in patients with intermediate-high- and high-risk pulmonary embolism, along with a significant early reduction of RV/LV ratio following treatment.