Cambodia Democracy and Accountability Act of 2003 - Directs that an additional $21.5 million in foreign assistance be made available for Cambodia above the FY 2004 budget request, but only after the Secretary of State certifies and reports to the congressional appropriations and foreign relations committees that new leadership in Cambodia has been elected in free and fair elections, and that Prime Minister Hun Sen is no longer in power.
Allows assistance to support a Khmer Rouge tribunal, trial, or other legal venue (venue) established by the Government of Cambodia with the assistance of the United Nations if the President determines and reports to such committees that such venue: (1) is not subject to the control or influence of the ruling Cambodian People's Party; (2) includes participation of judges of high moral character; (3) is supported by democratic Cambodian political parties; and (4) meets international standards of justice.
Directs the Federal Bureau of Investigation to resume its investigation into the March 1997 grenade attack in Cambodia, and to regularly report to such committees until such investigation is completed.