It is imperative that perfusionists thoroughly understand the hardware, disposables, and techniques available to the program. In collaboration with the surgeon and anesthesiologist, the perfusionist helps develop a cardiopulmonary bypass (CPB) plan for patients undergoing cardiac surgery. Key elements of this plan are defined before initiating CPB, with adjustments made as necessary based on the patient’s response and the adequacy of venous drainage and arterial return. Under ideal conditions, the plan may require minimal alteration during bypass. However, if issues such as inadequate venous drainage arise, modifications such as reducing pump flows and target temperature may be required. Throughout the procedure, the team must remain vigilant in monitoring both the patient and the circuit and communicate any concerns effectively. This chapter provides an overview of key considerations for pediatric CPB.