Background: Cultivating staff's professional English has become an imperative and challenging issue in English as a Foreign Language (EFL) countries. English for medical professionals is also the common language around the world for publishing new medical knowledge or reports. Therefore, Medical English for Health Professionals (MEHP) is a crucial required professional training program in nursing education. Its purpose is to improve nursing students' professional English so that they can directly understand the clinical medical information related to patients, thereby reading the latest international medical knowledge and participating in research themselves. Objective: The MEHP program is commonly conducted in a large-scale class using the lecturing approach, which is a passive learning mode lacking opportunities for individual students to experience learning contexts and to receive advice and guidance from the teacher. To solve this problem, the present study proposed a motivation model-based professional English gaming approach. Method: To verify the effects of the proposed approach, a quasi-experiment was conducted in an MEHP program of a university to explore the effects of the approach on nursing students' learning achievements. In addition, the higher and lower achievers' behavioural patterns, as well as their perceptions of the learning approach, were investigated. Results and Conclusions: The results showed that the motivation model-based digital gaming approach improved the students' professional English achievements in the "application" dimension as well as their positive perceptions of learning professional English more than the conventional learning approach. Moreover, when learning with the proposed approach, the higher achievers revealed more positive behavioural patterns than the lower achievers. The main contributions of the study are the proposal of a motivation model-based digital gaming approach, and showing the effectiveness of the proposed approach in helping trainees gain a deeper understanding of professional English and facilitating their positive learning behaviours in a course for medical English.