The cause was complications from multiple myeloma, according to a statement issued by the UCLA Athletic Department.
"No one ever did the job with more integrity than Pete Dalis," said Donahue, who spent 28 years at the university as a head coach, assistant coach and player. "Pete never put the athletics department ahead of the university. He would make that perfectly clear, whether you liked or didn't like it.
"Whatever decision had to be made, it had to be made in the best interest of the university."
That was never more clear than in 1996, when basketball coach Jim Harrick, who had won the NCAA title in 1995, was fired for lying about who attended a recruiting dinner and then attempting a cover-up.
Dalis was born in Los Angeles on Dec. 8, 1937. His parents, Tom and Anastasis, were Greek immigrants. He attended Manual Arts High School before enrolling at UCLA. He remained on the Westwood campus from 1955 until 2002, either as a student or an employee.
"Pete was a great representative of this university and an outstanding athletic director who always put the welfare of student-athletes at the forefront," current UCLA Athletic Director Dan Guerrero said in a statement. "On a personal note, he was very gracious with his time during my early days as athletic director and I always appreciated it."
Among Dalis' achievements as athletic director was the construction of the Morgan Center, which provided coaches and staff with office space. It was completed in 2000 and included an academic center for student athletes and a UCLA Hall of Fame.
"He wouldn't compromise his principles or beliefs to win a game or build a facility or anything like that," Donahue said. "He was a guy who believed that athletics had a place in the campus community, but as one of the many members of the university."
Dalis also had an influence on what was then the Pacific-10 Conference, now the Pac-12. He chaired the television committee and helped negotiate long-term contracts with ABC and Fox Sports Net that brought $200 million to the conference.
Dalis was inducted into the National Assn. of Collegiate Directors of Athletics Hall of Fame in 2010 and the UCLA Hall of Fame in 2008.
He is survived by his wife, Margaret Wigmore Dalis, whom he married in 1993, and her two children; and his brother Gus.