The ceremony began with a somber procession in front of the police department.
Inside, speakers paid tribute to the 51 officers who paid the ultimate price over the last 150 years to protect the people of Oakland.
But Chief Anthony Batts said it was not a day to be sad.
"This is a time to actually celebrate, a time to celebrate my heroes, your heroes, those brave souls who have given their lives to the city of Oakland," he said.
One by one, the names of every officer killed in the line of duty were read, including the most recent, the four men killed last March in the East Oakland shootout.