While once considered solely a concern of law enforcement agencies; money laundering, tax evasion and secrecy jurisdictions are now perceived as important obstacles to development. Dealing with illicit financial flows is an important aspect of the policy coherence agenda in international development, and developed country governments have made international commitments to tackle the problem Reforms and actions are necessary both in developed and developing countries, and this Brief looks at the experiences of some bilateral agencies that have begun to implement the illicit financial flows-agenda. Promising areas to engage in include support for improving tax systems and strengthening anti-monely laundering programmes.