Many members of the United Nations staff arriving with young families found unexpected difficulties with the school system in New York.

Among them was K. T. Behanan and his wife, who arrived from India in May 1947 with their five-year-old son to help the UN's Trusteeship Council with educational policy.

[7] Emphasis is placed on preparation for the IB exams during high school, for which virtually all seniors sit (full Diploma or Certificate).

All children are required to be interviewed and assessed in-person at UNIS, in addition to consideration of official school reports, if any.

It was previously located in a former school building at 1311 First Avenue, on East 70th Street, in Lenox Hill, Manhattan.

In 1964, the Ford Foundation offered a conditional donation of $7 million for a new school building at the headquarters of the United Nations, near an existing playground;[12] Sweden and Libya also contributed funds.

[20] The building was constructed on a platform that had been previously built for the planned school with a $1-million grant from the Rockefeller Brothers Fund.

The location was formally occupied by Pier 73, to which was docked the SS John W. Brown, a former Liberty ship that was being used as an annex for the Food and Maritimes Vocational High School.