The main focus of this study is to explore the use of Spherical Video-based Immersive Virtual Reality (SV-IVR) in investigating learners' fluency and vocabulary acquisition among sophomores in English as a Foreign Language (EFL) classrooms in higher education in Indonesia. Data were collected through 360-degree panoramic Virtual Reality (VR) observational assessments and vocabulary recall tasks, where participants were asked to mention words based on the video content they viewed in the SV-IVR environment. The analysis employed quantitative descriptive methods according to the participants' responses and observations. The data was analysed based on the general service list (GSL), academic word list (AWL), academic vocabulary range, knowledge-based vocabulary list (KVL), and word forms. The results illustrated that learners predominantly expressed high-frequency nouns, indicating a robust foundational vocabulary appropriate for routine communication. The focus on concrete nouns corresponds with their nature of being easier to illustrate than other parts of speech, including verbs and adjectives. As learners progressed in vocabulary acquisition, they started integrating more specialized and context-specific terminology, though their utilization of less common vocabulary remains restricted. The research also indicated that SV-IVR environments increased the connections between words and their visual or functional characteristics, facilitating vocabulary retention and recall.