On August 15, 2003, he was appointed to the Oregon Supreme Court to replace Susan M. Leeson who had resigned. Appointed by governor Ted Kulongoski, he won election to a full six-year term in 2004, winning 60 percent of the vote. He ran unopposed for re-election in 2010, winning a second six-year term. In addition to his judicial work, Kistler has taught state constitutional law as an adjunct professor at Lewis & Clark Law School in Portland, Oregon. He is a former member and vice-chair of the Oregon Board of Bar Examiners and a former member of the National Association of Attorneys General Working Groups on criminal law, federalism, and free speech; he served as chair of the working group on free speech.