Department of Homeland Security Procurement Improvement Act of 2007

Department of Homeland Security Procurement Improvement Act of 2007 - Amends the Homeland Security Act of 2002 to require: (1) the Chief Procurement Officer to provide homeland security procurement training to acquisition employees, including establishing training objectives, standards, requirements, and courses; and (2) the Secretary of Homeland Security to establish a Council on Procurement Training to make policy and training curriculum recommendations.

Directs the Secretary to require any offeror for a contract to provide goods or services to the Department of Homeland Security (DHS) to submit, as part of the offeror's bid: (1) an attestation disclosing any substantial role the offeror, the offeror's employees, or any corporate parent or subsidiary may have played in creating a solicitation, request for proposal, or statement of work or objectives for DHS; (2) a description of safeguards used to prevent the offeror from receiving information through such role that could provide an undue advantage in submission of a contract offer; and (3) a written certification indicating whether the offeror is in default or delinquent on any tax payment to the federal government.

Requires the Secretary to: (1) consider the contractor's past performance based on a review of information submitted regarding performance of government and private sector contracts; and (2) contact the relevant official who administered each such contract performed during the five-year period preceding the review.

Requires the Secretary to review, strengthen, and issue DHS-wide guidance on the policy governing the use of DHS purchase cards by employees to conduct official business.

Directs the Comptroller General to report to Congress on DHS contracting processes.