Objectives: Brain gliomas are among the tumors with the worst prognosis, and their incidence is increasing. Postoperative temozolomide-based chemoradiotherapy for grades 3 and 4 gliomas extended overall survival (OS) by approximately two months. An increasing number of clinical trials are investigating molecular-based therapy. Recent studies have demonstrated the involvement of Golgi apparatus proteins, including MYO18A (myosin-18A), in processes associated with abnormal proliferation, migration, apoptosis evasion, and angiogenesis promotion. The aim of this study was to investigate whether MYO18A has prognostic value in patients treated for brain gliomas. Methods: The research material in the work included tumor samples taken during neurosurgery and blood samples from 45 patients treated for brain gliomas with grade of 1 to 4 according to WHO, which were used to determine the expression of MYO18A mRNA (messenger ribonucleic acid). Expression of MYO18A was presented as fold changes in RQ (relative quantification) mRNA levels. Results: This study showed higher MYO18A values in patients diagnosed with grade G4 glioma among those with a shorter progression-free survival (PFS) time and those living shorter than the group average. However, statistically significant differences were achieved only for PFS for the MYO18A RQ feature (PFS = 4.64, SD = 2.16 vs. PFS = 15.83 and SD = 7.27, p = 0.0231). Also, a positive correlation was demonstrated between tumor volume and MYO18A expression. Conclusion: The level of expression of MYO18A can be considered a prognostic factor for PFS in patients treated for G4 gliomas, because higher MYO18A expression was associated with earlier recurrence.