Once a patient has been admitted for surgery, depending upon their pre-operative assessment, they may require a period of optimization in hospital before surgery. Pre-operative optimization will focus the clinical teams on incremental adjustments to baseline physiology and testing to ensure that the patient is in optimal clinical condition prior to surgery. The nursing care of such patients will rely upon surgical knowledge of body systems, such as cardiovascular and respiratory, alongside fluid and electrolyte management, nutrition, and pharmacology. This chapter guides the nurse in the assessment process and the skills required in the management of a high-risk surgical patient.