Background: Steroids are widely used in medicine because of their anti-inflammatory and immunosuppressive properties; however, they have numerous adverse effects. In neuro-oncology, dexamethasone is the first-line treatment for vasogenic edema caused by malignant brain tumours. This retrospective chart review investigated the risks and benefits of perioperative steroids in the surgical treatment of malignant brain tumours. Methods: All patients (age ≥ 18 years) who underwent a craniotomy for the treatment of a malignant brain tumour at Windsor Regional Hospital between 2012 and 2020 were assessed for eligibility for this retrospective study. Baseline patient characteristics, cumulative perioperative steroid dose, and postoperative outcomes were recorded from electronic medical records (n = 362). Statistical analysis was performed using SPSS. Results: Patients who received a higher cumulative perioperative steroid dose (≥ 80 mg) had a significantly higher rate of postoperative complications compared to those who received a lower dose. These included wound dehiscence, postoperative brain edema on imaging, unplanned return to the operating room, and readmission within 30 days. Conclusions: Steroids are important medications in neuro-oncology, but they are not without potential complications. The findings of this study highlight the need for careful consideration when using steroids in patients undergoing surgical treatment of a malignant brain tumour.