In 1949 he then moved to Washington, D.C. and joined the staff of the IMF, as Assistant Chief of the Latin American Division in the Research Department.
He left after just two years to return to Brazil to organize the Brazilian Institute of Economics at the Getúlio Vargas Foundation in Rio de Janeiro.
By this time, he was one of the leading figures in Brazilian economics, known for his intellectual prowess and keen wit, and had developed a worldwide reputation.
In July 1966, he went back to the IMF for good, initially as alternate to the executive director for Brazil, Mauricio Chagas Bicalho.
In November, he was elected by Brazil, Colombia, the Dominican Republic, Haiti, Panama, and Peru to succeed Mr. Bicalho as executive director.
Kafka was elected executive director sixteen times, through many major shifts in the balance of political power in Brazil and the other countries in his constituency.
For more than three decades, he was a mentor to executive directors and staff, a voice of reason on the board, and a master at brevity of expression in his interventions.