The proposed study will be a multi-institutional, phase I/II study of disulfiram (DSF) for patients with presumed glioblastoma multiforme (GBM) based on magnetic resonance imaging (MRI) or biopsy, including administration before surgery and during adjuvant chemoradiotherapy. Patients will be treated with 3 days of preoperative DSF/copper (Cu) prior to their surgery (or biopsy), which will be followed by collection of blood and tumor samples during surgery for analysis of drug uptake. After the surgery, patients will receive standard radiation therapy (RT) and temozolomide (TMZ) with the addition of concurrent DSF/Cu.