This article examines Haj Amin al-Husseini’s involvement in the Holocaust, his ties to the Muslim Brotherhood, and the Brotherhood’s post-Holocaust influence on the spread of exterminationist Jew hatred. The article examines the connection between the Nazis and the Muslim Brotherhood facilitated by al-Husseini, showing the pivotal nature of the Arab Revolt of 1936 – 1939 in these relationships. By then the Brotherhood was sending delegations to the Nuremberg rallies and distributing the Protocols of the Elders of Zion and Arabic-language selections from Mein Kampf. The article then explores al-Husseini’s direct collaboration with the Nazis and participation in the Holocaust. This begins with his instigation of a Nazi-backed coup in Iraq in April 1941, which was followed by the slaughter of hundreds of Jews in Baghdad. From there we go to al-Husseini’s first meeting with Hitler in November 1941 and his work with Himmler in organizing Muslim SS killing units in the Balkans. This section ends with al-Husseini’s hero’s welcome as a Nazi war criminal in July 1946, when he was once again embraced by the Muslim Brotherhood. Finally, the article moves to the post-war years, with al-Husseini’s recruitment and indoctrination of Yasser Arafat in the Brotherhood. This article considers the Brotherhood’s influence on the Palestinian Liberation Organization and Hamas in the spread of an exterminationist agenda inspired by the Nazis.