This study explores the effectiveness of Virtual Reality (VR) in Chinese as a second language (CSL) vocabulary learning from the international students' perspective. A new theoretical framework of VR-based vocabulary learning was designed and verified to serve the investigation. A total of 30 international students learning CSL in a Chinese university participated in the study. Data were collected through vocabulary tests, a VR-based vocabulary learning questionnaire, and semi-structured interviews. Findings indicate that the VR approach can effectively facilitate students' vocabulary learning and retention, as well as a positive learning experience. VR provides an authentic and repetition-enabled learning context. In an immersive environment, a higher rate of engagement in interactions and multimodal, immediate, and learner-friendly scaffolding benefit students' VR-based vocabulary learning. Results also indicate that VR can motivate students to be actively involved in learning and build their language skills despite some challenges. Investigation of a wider range of learners with different backgrounds and language levels, and the differences between VR-based learning and traditional learning is recommended for future research. Additionally, CSL teachers' perceptions are worthy of consideration.