Money laundering is a serious threat to the financial system. It is often referred to as the “dirty little secret” of the financial world. In this chapter, we will examine what anti-money laundering is in general, what makes an anti-money laundering program work, and how risk assessment fits into anti-money laundering compliance. We will also discuss the principles and practices discussed here, as they are the building blocks for a more resilient and secure financial system, one that can withhold the pressures of bad actor activity and uphold the trust of its participants.