Zijlstra continued to be active in politics and in September 1966 was nominated as the next President of the Central Bank, however after a political crisis was persuaded to lead an interim cabinet until the next election. Zijlstra formed the caretaker Cabinet Zijlstra and became Prime Minister of the Netherlands and dual served as Minister of Finances taking office on 22 November 1966. Before the election of 1967 Zijlstra indicated that he wouldn't serve another term as Prime Minister and opted to accepted the nomination as head of the Central Bank. Zijlstra left office following the installation of the Cabinet De Jong on 5 April 1967 and was confirmed as chief of the Central Bank serving from 1 May 1967 until 1 January 1982.