Born in the Bronx, New York, Joseph J. DioGuardi moved to Westchester County with his Albanian immigrant parents, brother, and sister in 1957. He is a 1958 graduate of Fordham Preparatory School, and in 1962 he graduated with honors from Fordham University.

DioGuardi served for twenty-two years, twelve of them as a tax partner, with the international accounting firm of Arthur Andersen & Co., one of the first public advocates of governmental fiscal responsibility. In November 1984, he brought his extensive professional and volunteer experience to Congress, when he became the first practicing certified public accountant ever elected to the U.S. House of Representatives.

In Congress, DioGuardi took the lead in sounding the call for truth in federal budgeting, accounting, and reporting and in bringing financial accountability to Capitol Hill. He was the original author of the Chief Financial Officer's Act, signed by President George Bush in 1990, which mandated the assignment of a CFO to each major department and agency of the U.S. government. Charles Bowsher, former Comptroller General of the General Accounting Office, said in testimony before the U.S. Senate that since the enactment of the bill, "we have seen important progress in directly confronting serious financial management weaknesses."

DioGuardi has distinguished himself by finding bipartisan solutions to difficult problems. On issues of local concern, he founded and cochaired the Congressional Long Island Sound and Hudson River Caucuses, which secured vital increases in federal support for these embattled waterways. In 1986, with the late Democratic Congressman Mickey Leland, DioGuardi initiated legislation to confer Congressional Medals of Honor on Black World War I and World War II military heroes, thereby correcting an historic injustice. More recently, he cofounded with Congressman Jerrold Nadler the New York Task Force for Port, Rail, and Industrial Development in order to restore lost jobs to New York's manufacturing and transportation industries.

DioGuardi is an advocate for the human rights and self-determination of oppressed peoples in the Balkans. Since 1989, he has made fifteen trips to the region. As president of the Albanian American Civic League, he and Congressman Tom Lantos made the first official trip to Albania in fifty years, and he helped open the doors to democracy in this former Communist dictatorship. In August 1990, DioGuardi persuaded Bob Dole and six other U.S. senators to visit the two million Albanians in Kosovo. In September 1996, he returned to Albania with Congressman Benjamin Gilman, chairman of the Committee on International Relations, to meet with President Sali Berisha to discuss Albanian national security and minority rights for the ethnic Greeks in southern Albania. In June 1997, Dio Guardi led a delegation to monitor the national elections in Albania and in August, 1998 he traveled to northern Albania to assess the humanitarian crisis emanating from the war in Kosovo, at the request of Congressman Dana Rohrabacher.

Since leaving Congress in 1989, DioGuardi has established a nonpartisan foundation, Truth In Government, through which he continues his crusade for federal fiscal reforms. The author of Unaccountable Congress: It Doesn't Add Up, DioGuardi is a frequent speaker on fiscal responsibility and public accountability. In August 1994, as a keynote speaker at the annual conference of the American Accounting Association, DioGuardi persuaded professors of accounting to play an active role in federal budgeting and financial management. In May 1996, he returned to Washington as a keynote speaker on federal financial management reforms before the Institute of Management Accountants (formerly the National Association of Accountants). In April 1997, the Texas Society of CPAs published an article by DioGuardi in Today's CPA on the real magnitude of the national debt.

DioGuardi is the recipient of numerous awards and honors, including investiture as a Knight of Malta in 1979, the International Humanitarian Award The Boys Towns of Italy in 1986, the Outstanding CPA in Government Award from the New York State Society of CPAs in 1986, the Torch of Liberty Award from the New York State Conservative Party in 1987, the Outstanding Public Service Award from the Westchester County Republican Committee in 1987, the Westchester Irish Committee's Dedication to Peace and Justice Award in 1988, the Paul Harris Fellow Award of the Rotary Foundation of Rotary International in 1988, and the Annual Achievement Award of the Association of Government Accountants, Boston Chapter, in 1992.