Beginning in June 1950, Strauss became a financial adviser to the Rockefeller brothers, where his charter was to participate in decisions regarding projects, financing, and investing. For them, he assisted in the founding of, and served on the first board for, the Population Council. He was also involved in the negotiations with Columbia University that led to a sale and leasing back of real estate associated with part of Rockefeller Center. The relationship with the Rockefeller brothers would last until 1953. However Strauss felt the brothers treated him as a second-class asset and in turn he felt no loyalty towards them.