Justice Guy James Mangano graduated from St. John's University School of Law in 1955. He was awarded an Honorary Doctor of Law degree in 1983. From 1955 until 1958 he served as investigator and assistant counsel for the Joint Legislative Committee. He served on the New York State Assembly for Kings County from 1958 until 1962 and on the State Senate for Kings County from 1962 until 1965.
Mangano joined the bench in 1965 when he was appointed to the New York City Family Court, and served on the Family Court until 1968. In the following year he won election to the Supreme Court for the Second Judicial District, and was reelected in 1982 and 1997. From 1976 until 1978 he was Administrative Judge of the Criminal Term of the Kings County Supreme Court. He served as an Associate Justice of the Appellate Term for the Second and Eleventh Judicial Districts until he was designated to the Appellate Division, Second Department on January 22, 1979. On March 20, 1990, Justice Mangano was appointed Presiding Justice of the Second Department by Governor Mario M. Cuomo. He was re-designated as Presiding Justice on December 30, 1996 by Governor George Pataki. Following his retirement from the bench in 2001, Mangano joined the New York office of JAMS Arbitration, Mediation and ADR Services.
In addition to his judicial career, he was an adjunct professor of law at St. John's University School of Law from 1990 until 1996. His memberships have included the Brooklyn and American Bar Associations and the Executive Committee of The Council of Chief Judges. He has also served as President of the Council of Chief Judges and Chair of the Board of Governors of the New York Attorney Client Dispute Resolution Program.
Appellate Division, Second Department, 100th Anniversary. 19. The Historical Society of the Courts of the State of New York, 1996. Web. 15 May 2012. http://www.courts.state.ny.us/history/pdf/Library/Courts/App_Div_Sec_Dept_100th_Anniv.pdf.
"Guy James Mangano." The New York Red Book. Ed. George A. Mitchell. 95th ed. Guilderland: New York Legal, 1999. 498-99. Print.
"Hon. Guy James Mangano (Ret.)." JAMS Arbitration, Mediation and ADR Services, 2011. Web. 15 May 2012. http://www.jamsadr.com/mangano/.