He was a law clerk to Judge Bruce F. Beilfuss, Wisconsin Supreme Court from 1979 to 1980.
He was a staff attorney of United States Court of Appeals for the Seventh Circuit from 1980 to 1982, thereafter entering private practice in Wisconsin from 1982 to 1987.
He was confirmed by the United States Senate on April 25, 2002, and received his commission on May 1, 2002.
[1] In November 2016, Griesbach dissented when Circuit Judge Kenneth Francis Ripple, joined by District Judge Barbara Brandriff Crabb, found that the high number of wasted votes created by the 2011 Wisconsin State Assembly redistricting was unconstitutional partisan gerrymandering.
[2] The opinion was vacated and remanded by the United States Supreme Court on June 18, 2018.