Evidence-based medicine integrates the best available data in decision making, with the goal of minimizing physicians' and patients' subjectivity. In 2006, the American Society of Clinical Oncology edited clinical practice guidelines for the use of larynx preservation strategies. The objective of this review was to evaluate the current levels of evidence for glottic squamous cell carcinoma. Current guidelines for early stage glottic cancer are based on low-level evidence. Conservation surgery (open or transoral) and radiation therapy are all valid options for T1 and selected T2 lesions. For advanced lesions, surgery and combined chemotherapy and radiation are options. High-level evidence favors combined chemotherapy and radiation therapy or altered fractionation radiation therapy as nonsurgical strategies for organ preservation, compared with radiation therapy alone. The optimal combination of chemotherapy, targeted therapy, and radiation therapy remains to be demonstrated, however, and for high-volume tumors, total laryngectomy may still be warranted.