This study investigates the impact of a 3D virtual learning environment based on Second Life on student motivation and achievement in learning English as a second language. Twenty-one university students participate in this study, with the support of an English instructor. The Motivated Strategies for Learning Questionnaire (MSLQ) was used to evaluate students’ intrinsic and extrinsic goal orientation and self-efficacy in Second Life. The pre-test and post-test were used to assess students’ learning achievement. The results showed that students’ intrinsic and extrinsic goal orientations in English learning in Second Life had a positive influence on their self-efficacy. In addition, students’ self-efficacy of English learning in Second Life was found to positively relate to their learning achievement. Moreover, students’ intrinsic and extrinsic goal orientations were found to significantly influence their learning achievement via self-efficacy. In other words, instructors can utilize Second Life to enhance student motivation and achievement in English learning. | Student motivation and achievement in learning English as a second language using Second Life