Fordham University has seen several cases of the mumps hit its Rose Hill campus recently.
University Health Services reported seven cases in the past two days and one last month.
They say all eight students had been vaccinated against mumps - a requirement before attending the school.
But the vaccine doesn't offer full protection.
School health officials say all of the students were sent home or isolated from the rest of the 7,000 students.
Mumps symptoms include fever, muscle aches and loss of appetite.
Those affected are usually contagious for two days before experiencing symptoms, and for five days after.