The effectiveness of critical care ultrasound has been demonstrated and training for it is urgent. Critical Care Ultrasound Study Group (CCUSG) has been dedicated to ultrasound training. The aim of the study was to evaluate course structure and training effect and provide improvement suggestions for future training.A multicenter retrospective study was conducted. All participants went through a 2-day training curriculum based on the critical care ultrasonic examination (CCUE) protocol. Pre- and post-class evaluation were applied and data were collected. Non-parametric tests were adopted for the comparison, and a Generalized Linear Model (GLM) was used for further analysis.A total number of 792 trainees, with a mean age of 35.8, participated in the study. There were more males in the study population. Most of the trainees were attendings, and most of them had bachelor's degrees, worked at tertiary hospitals and had a mean working experience of 6.9 years. The scores of all trainees were improved to various degrees after the course. An increase from 50% to 72% (P≤0.001) was seen in theory test scores. All the competency assessment scores, including IAS (34% to 50% for cardiac images and 30% to 60% for pulmonary images), IPS (30% to 50%) and AAS (31% to 44%), were improved. A questionnaire after class suggested that 88.0% of the participants found the training course very useful.2-day training course can improve the ability of physicians to assess critically ill patients with the help of the ultrasound.AJTR Copyright © 2024.