Recently, ultrasound has been increasingly used in emergency departments (EDs) due to its promising noninvasive and portable characteristics. Traditional ultrasound training is a complex process that requires knowledge gain, development of psychomotor skills, and visual perception. However, it usually takes a long time for a novice sonographer to finish an ultrasound training program, and the training may target on limited applications. The e-learning, information, and communication technology on digital devices to support learning may overcome the limitations of the traditional ultrasound training. In this article, we design and implement a mobile e-learning platform for ultrasound training, namely MEUS, to address the abovementioned issues. The MEUS provides an interactive learning environment for teachers and learners. Teachers and learners can access MEUS and receive real-time feedback anywhere and anytime through a mobile device or desktop. We implement a multistage learning process. To evaluate the learning performance of using the platform, we add the MEUS platform as a part of the emergency ultrasound training course with the Post Graduate Year (PGY) program in the ED at the National Taiwan University Hospital. Our study shows that the MEUS platform can significantly increase the learning efficacy of the PGY students.