Our audit assessed programs implemented by the Federal Bureau of Investigation (FBI) and National Security Division (NSD) to identify, investigate, and prosecute terrorist financing. We found that the FBI and NSD have mechanisms to ensure terrorist financing-related information is shared and coordinated with each other and with other relevant law enforcement organizations and intelligence agencies. However, we found that the FBI could improve some case management practices associated with investigating terrorist financing. In August 2005, the FBI Terrorist Financing Operations Section (TFOS) recommended that FBI field offices consider the use, where appropriate, of six basic financial-related investigative techniques when conducting counterterrorism investigations. According to TFOS, these investigative techniques are: (1) FBI database inquiries, (2) FinCEN data inquiries, (3) government-wide database inquiries, (4) public and commercial database inquiries, (5) credit history checks, and (6) the identification and review of bank account activity. The FBI directed each field office to focus on financial information in counterterrorism cases and establish a financial investigative sub-file for all counterterrorism investigations. Also, each FBI field office was instructed to designate a Terrorist Financing Coordinator to serve as a liaison between the field offices and the Terrorist Financing Operations Section. The case files we reviewed did not always contain documentation of the use of financial-related investigative techniques or for not using techniques when it appeared unnecessary to do so. According to the FBI, Special Agents are not required to document each action it deems unnecessary to take and doing so may be unduly burdensome and inefficient. However, in our judgment better-supported case files enable succeeding Special Agents and FBI managers to determine whether a given counterterrorism investigation included an appropriate financial focus. In addition, clearly documenting the use of financial-related investigative techniques or valid reasons for not using these techniques is consistent with FBI investigative and case-file management requirements. FBI field offices are required to ensure that all reasonable investigative techniques have been exploited during each terrorism investigation. When closing such investigations, field office staff affirms that they have exhausted reasonable and practical intelligence collection methods and that investigative methods and techniques initiated have been completed or discontinued. We determined that the FBI documented the use of or provided a valid reason for not using FBI database inquiries for 100 percent of the case files reviewed. For the remaining five techniques, we or the FBI identified documentation of the use of or valid reasons for not using the techniques in most but not all sampled cases. The FBI issued a directive to focus on the financial aspects in counterterrorism cases by creating a specific sub-file for all counterterrorism investigations, but we found that Special Agents did not always adhere to this directive. We also found that during the review period Terrorist Financing Coordinators did not routinely review counterterrorism cases to ensure the field offices implemented the financial focus directive for counterterrorism investigations. We believe it is important that all criminal and counterterrorism cases be reviewed for a potential nexus to terrorist financing so that FBI management can seek to achieve a consistent approach to applying financial-related investigative techniques. Our review found that the coordinators did not always perform their duties as intended by the FBI, performed unrelated collateral duties, and were not always selected in accordance with TFOS guidance.