Critical care pharmacists encounter solid organ transplant patients at all stages of transplant and play an essential role in optimizing care in collaboration with the intensive care and solid organ transplant teams. In addition to typical patient care responsibilities, critical care pharmacists may be involved in transplant evaluations, immunosuppression monitoring, and in discharge planning and education per CMS regulations. Understanding the center and organ-specific immunosuppression protocol is key to anticipating which immunosuppression agents patients will receive and possible need to tailor to patient-specific needs. Most patients will receive induction immunosuppression at the time of transplant followed by lifelong maintenance immunosuppression typically with calcineurin inhibitors. It is important for pharmacists caring for transplant recipients to understand the pharmacokinetics of calcineurin inhibitors to ensure patients receive proper medication dosing and monitoring. Management of immunosuppression in transplant recipients is a constant balance of rejection and infection while adjusting regimens due to adverse drug effects. Transplant recipients may experience neurological complications due to underlying cause of organ failure or due to use of calcineurin inhibitors. Long-term use of calcineurin inhibitors also puts these patients at higher risk of acute kidney injury and renal failure. Finally, transplant recipients are also at increased risk for thrombotic and cardiovascular complications with management of these being similar to the general non-transplant population. This chapter will examine basic concepts for solid organ transplantation including immunosuppression and transplant complications including rejection, neurologic, thromboembolic, acute kidney injury and renal failure, and cardiovascular.