Digital technologies offer innovative opportunities for recovering and maintaining intellectual and mental health. The use of a multitask approach that combines motor component with various cognitive tasks in a virtual environment can optimize cognitive and physical functions and improve the quality of life of cardiac surgery patients. This study aimed to localize current sources of theta and alpha power in patients who have undergone virtual multitask training (VMT) and a control group in the early postoperative period of coronary artery bypass grafting (CABG). A total of 100 male CABG patients (mean age, 62.7 ± 7.62 years) were allocated to the VMT group ( = 50) or to the control group ( = 50). EEG was recorded in the eyes-closed resting state at baseline (2-3 days before CABG) and after VMT course or approximately 11-12 days after CABG (the control group). Power EEG analysis was conducted and frequency-domain standardized low-resolution tomography (sLORETA) was used to assess the effect of VMT on brain activity. After VMT, patients demonstrated a significantly higher density of alpha-rhythm (7-9 Hz) current sources (t > -4.18; < 0.026) in Brodmann area 30, parahippocampal, and limbic system structures compared to preoperative data. In contrast, the control group had a marked elevation in the density of theta-rhythm (3-5 Hz) current sources (t > -3.98; < 0.017) in parieto-occipital areas in comparison to preoperative values. Virtual reality-based multitask training stimulated brain regions associated with spatial orientation and memory encoding. The findings of this study highlight the importance of neural mechanisms underlying the effectiveness of multitask interventions and will be useful for designing and conducting future studies involving VR multitask training.