Many patients refuse blood or blood products because of religious beliefs or fear of complications. At Hennepin County Medical Center, a multidisciplinary team developed a Bloodless Surgery Medicine Guideline (BSMG) to help identify those who refuse blood products, guide medical decision-making, improve documentation of informed consent or refusal, and ensure continuity of care for patients. To our knowledge, this is the first documentation of a guideline for managing informed consent for or refusal of blood or blood products in trauma patients. This article discusses the development of and legal rationale for two key components of the BSMG: an informed consent/refusal algorithm and a blueprint for discussing the use of blood or blood components with patients and documenting their decisions.