The enactment of the Japanese Imperial Government Disclosure Act (P.L.106-657) and the issuance of Executive Order 13110 (Jan. 11, 1999) aimed at making U.S. government records related to Japanese war crimes and war criminals in World War II more accessible. Records surveys implementing these requirements disclosed that there were relatively few remaining security-classified relevant documents waiting for disclosure. On the other hand, better identification of relevant documents and improved access to these records was a primary goal of the White House. The Interagency Working Group (IWG) staff took up the admonition from the National Security Advisor that “Agencies should bring to light hitherto unknown relevant unclassified or declassified records encountered in the course of the search for relevant classified records.” In selecting documents, the IWG Staff focused on several subjects and topics that have longstanding interest and concerns for researchers: Japanese research and experiments in biological warfare (BW) Japanese instigation of biological warfare attacks in World War II Japanese biological warfare experiments on living humans and animals Japanese atrocities against prisoners of war Japanese atrocities against civilian populations Allied decisions to hold Japanese responsible for war crimes Allied decisions to hold war crimes trials Allied decision to consider Emperor Hirohito as a person responsible for war crimes Allied decisions to investigate specific Japanese scientists and military personnel for BW crimes American POWs held at Mukden POW Camp Hoten and any evidence of BW experiments on them Some subjects of current interest, such as “comfort women,” were specifically searched for, but with little success. This collection will continue to expand as new documents are discovered.