OBJECTIVE: To plan neurosurgery that preserves brain function, it is crucial to obtain accurate images of the areas surrounding the eloquent tumor. The study’s objective was to compare the diagnostic capabilities of preoperative functional magnetic resonance imaging (fMRI) to a comprehensive evaluation of morphological magnetic resonance imaging (MRI) data. The objective was to assess the relative usefulness of both techniques in the preoperative diagnostic process. METHODS: A thorough examination of the neurological system was performed on 77 individuals who had Rolandic lesions, utilizing a magnetic field strength of 1.5 Tesla. The examination was standardized and included both functional and structural components. The central part of each hemisphere was precisely located through the use of six morphological markers and three functional markers. RESULTS: The localization of the motor hand region by fMRI was successful in 76 out of 77 patients, greatly exceeding structural MRI analysis, which was successful in only 66 out of 77 patients (p-value < 0.002). Furthermore, 96% of patients had extra diagnostic data about tongue representation from fMRI, and 97% had additional diagnostic data regarding foot representation from fMRI. The preoperative risk assessment using fMRI and the postoperative clinical outcome was shown to be positively correlated in 88% of cases. CONCLUSIONS: The research findings suggest that using preoperative functional magnetic resonance imaging (fMRI) can provide a more accurate assessment of the location of the motor cortex in relation to the brain tumor compared to traditional 3D MRI scans. This can simplify the preoperative evaluation of the potential risks and benefits of surgery, and make it easier to plan for a surgery that preserves neurological function. Although the study did require a longer imaging time, the results also indicate that fMRI may help to reduce hospital stays and minimize surgical complications.