[2] Paez was confirmed by Senate on March 9, 2000 by a 59-39 vote,[3] more than four years after President Clinton first nominated him to the United States Court of Appeals for the Ninth Circuit.

[2] On August 6, 2004, Paez ruled that Maricopa County Sheriff Joe Arpaio's internet broadcasting of pretrial detainees violated the 14th Amendment.

Paez ruled that the Army could not use the "discretionary function exception" as a defense because it failed to clear the parking area in one of its apartment complexes despite specifying a duty to do so "once a year, before the end of March".

[7] In a 2009 decision, he held that a San Francisco resolution urging the Vatican to withdraw a directive against gay adoptions does not violate the Establishment Clause.

[8] In a 2011 decision, he wrote the majority opinion upholding a lower court's blocking of the most controversial parts of the Arizona SB 1070 anti-illegal immigration law from taking effect.

Paez would have ruled that the 5th Amendment's Due Process Clause guarantees the right to appointed counsel for minors in most removal proceedings, an issue the majority declined to reach.

He wrote "The majority has unduly burdened students with disabilities with having to proceed with a full hearing at the administrative level for claims that do not implicate a FAPE simply because the discrimination they suffer happens at school.

On February 4, 2022, Paez dissented from an opinion by Judge Milan Smith determining that former United States Secretary of Education Elisabeth DeVos could not be forced to sit for a deposition in a case arising out of delays in making decisions on student loans.