Research into the effects of role-play games has indicated their role in facilitating young learners’ grammar learning. However, an intriguing concern is how to implement this method of teaching English grammar within the Vietnamese context. Little research has examined the effects of integrating role-play games into grammar lessons and explored learners’ perceptions of this instructional approach in Vietnam. The current study therefore aims at investigating this area of interest. A quasi-experimental design was employed to explore the effects of role-play games on young learners’ grammar learning. The participants were 72 fifth-graders from a public primary school in the Mekong Delta of Vietnam. Data collected in this study include pre-and post-tests, questionnaires, and semi-structured interviews. The quantitative analysis reveals that young learners in the treatment group made progress in their grammar learning compared with those in the control group. The findings reveal that role-play games influenced young learners’ grammar learning and these learners perceived the effects of role-play games on their grammar learning. Pedagogical implications for teachers and school administrators are made. Keywords: role-play games, young learners, grammar learning