She was appointed to the Oregon Supreme Court by Oregon Governor Ted Kulongoski and was sworn into office on October 9, 2006, to replace Justice R. William Riggs who had retired. Walters was the first female justice on the court since 2003 when Susan M. Leeson left the court. In 2007, Walters was elected as the president of the Uniform Law Commission, becoming that organization's first female president. Walters won election to a full six-year term on the court in 2008, and was re-elected in 2014.