He served as a judge of the Court of Common Pleas, Allegheny County, Pennsylvania, from 1974 to 1978.

[1] On March 22, 1978, Ziegler was nominated by President Jimmy Carter to a seat on the United States District Court for the Western District of Pennsylvania vacated by Judge Rabe Ferguson Marsh Jr. Ziegler was confirmed by the United States Senate on May 1, 1978, and received his commission the following day.

He assumed senior status on October 1, 2001, serving in that capacity until his retirement from the bench on May 31, 2003.

Ziegler served as a member of the Judicial Conference of the United States for three years, and the Judicial Council of the Third Circuit for seven years.

[1] Along with being an outstanding Judge, Judge Ziegler was a great, kind, considerate and thoughtful mentor and professor to law students and new lawyers.