Prospective memory (PM), defining the currently conceived intention of a future action, is crucial for daily functioning, particularly in aging populations. This study develops and validates a virtual reality prospective memory training (VR-PMT) system that integrates visual imagery training (VIT) and virtual reality training (VRT) to enhance the PM abilities of users. The framework is designed to progressively challenge users by simulating real-life PM tasks in a controlled VR environment. The VIT component is designed to improve the generation and utilization of visual imagery by users, while the VRT component provides PM tasks based on time and event cues within a virtual environment.The framework was evaluated on ten healthy adults (university students and elderly participants) over nine weeks. During the initial session, the baseline PM abilities of the participants were assessed using the memory for intentions screening test (MIST). The subsequent sessions alternated between VIT and VRT with increasing task complexity. The MIST scores were significantly positively correlated with task achievement, confirming the efficacy of the system. Imagery abilities were also strongly correlated with task performance, underscoring the importance of visual imagery in PM training.Usability and user experiences, evaluated on the Jikaku-sho Shirabe questionnaire and the user experience questionnaire, indicated an overall positive user experience but higher fatigue levels in elderly participants. This study demonstrates that the VR--PMT system effectively trains and assesses PM abilities by integrating VIT and VRT, supporting its potential for broader applications in clinical settings.