Dozens of students occupied the Registrar's Office. The group By Any Means Necessary (BAMN), a grassroots coalition to defend affirmative action, organized the sit-in.
Protesters demanded the university double the enrollment of under-represented minorities, including blacks and Hispanic students.
They also asked for charges stemming from an Occupy protest last year to be dropped.
Organizers had said they would not leave until their demands were met.
University police were called in as a precaution. However, all the students voluntarily left before the building closed at 5 p.m.