Background: The use of virtual reality (VR) has great potential for medical research and practice, which can help expand rehabilitation activities. This study aimed to evaluate the acceptability and feasibility of the original protocol VR multitasking cognitive training (CT) in both a healthy group and cardiac surgery patients. Methods: A specialized hardware and software complex was developed and tested on both a group of 25 practically healthy individuals, mean age 22.9 years (SD 2.57), and 25 cardiac surgery patients, mean age 62.2 years (SD 7.35). The participants were instructed to complete one session of multitasking CT within the VR complex. Psychometric testing and EEG studies were conducted. Results: All participants were highly accepting of the intended future use, attitude, and pleasure of the training. The healthy subjects demonstrated a statistically significant improvement in attention and spatial skills after VR (p ˂ 0.05). The EEG data revealed a significant increase in alpha power compared to pre-experiment levels (p ˂ 0.0001). The theta/alpha ratio significantly decreased after the VR multitasking CT as compared to the baseline (p ˂ 0.0001). Conclusions: The data obtained indicate that the original training protocol for multitasking CT using VR is acceptable and easy to use for both healthy individuals and cardiac surgery patients.