More than 22,000 runners took off in waves from the start line Sunday morning at CityScape retail complex. The 26.2-mile course takes participants through central Phoenix, Scottsdale and ends in Tempe Beach Park.
Other runners are participating in the half-marathon, 10K or two-person relay.
The Wallflowers and OK Go will be the headlining bands at the Finish Line Festival.
Organizers had a close call when the arrival of thousands of finishers' medals was put in jeopardy because of shipping delays at West Coast ports.
But the medals arrived in Phoenix on Saturday, just hours before the Rock `n' Roll 5K began.