Purpose: This study investigated the effects of an AR application (Civilisations AR) on EFL learners' oral proficiency in the dimensions of content, fluency, vocabulary, pronunciation, and grammar, as well as their attitudes and perceptions toward AR technology. Design: Utilizing a quasi-experiment, twenty-four EFL learners engaged in a role-playing activity as museum guides for six artifacts over a semester: twelve with the AR application and twelve without. Data collection included oral presentations recorded at six different times of the semester, the AR technology acceptance questionnaire, participants' reflection papers, and individual interviews at the end of the semester. Findings: Participants' oral proficiency has been improved in terms of content, vocabulary, and pronunciation when using the AR application compared to when not using it. They felt that the AR-assisted method encouraged active learning and stimulated their learning interest, and they were willing to incorporate the AR tool into their future education. Originality and Value: This study indicates that AR has the potential to enhance speaking skills in second language acquisition though it still needs improvement to meet more needs.