In the rapidly evolving landscape of educational technologies, Immersive Virtual Reality (iVR) stands out as a transformative tool for teaching and learning. The learner must actively engage, particularly when visual and auditory knowledge information is presented simultaneously. Generative learning strategies support learners in processing and integrating the information provided effectively and help them select, organize, and integrate information into a coherent mental model. Yet, learners often do not use such strategies spontaneously, so pre-training of the learning strategy is recommendable. IVR provides a spatial context for learning, where an essential strategy for promoting learning is to integrate auditory knowledge information into visually perceived space. We hypothesize that this can be done effectively through imagination, i.e., learners mentally visualize auditory information. This study investigated an imaginative pre-training strategy that targets integrating visual-spatial and auditory knowledge information. In a pre-post between-subjects design, we tested the effects of imaginative strategy pre-training. Students received either a pre-training (EG = 30) or no training (CG = 30) before exploring an iVR learning environment. Against our expectations, the EG did not outperform the CG on semantic and spatial knowledge. These findings may be explained by the demands on learners to process sensory input, and focus directed attention in a spatial iVR environment, suggesting that imagination strategies need to be anchored and complemented by other selection and organization strategies. This study contributes to a critical understanding of the possibilities and limitations of iVR in education, shedding light on the learners' processes and needs.