Ties that bound the communist parties in Iran and the Arab world to the Soviet Union have been subject of much study but what of the relations between these parties inside the Middle East? This paper presents an overview of the strong alliance between the Iranian and Iraqi communists, respectively organized in the Tudeh Party of Iran and the Iraqi Communist Party. The first major iteration of the alliance showed itself in the 1940s in the Arab-majority province of Khuzestan in Iran where the oil workers organized by Tudeh Party and supported by the Iraqi communists came up against the British owners of the Anglo-Iranian Oil Company and their allies in Baghdad and local Arab tribes in Iran. The relationship between the two parties was multi-faceted and expressed itself on political, intellectual and practical grounds. It also included moments of disagreements like the Zionist question to which the Iranian and Arab communists had sharply different approaches and over which they continued` to debate for years (Both Tudeh and ICP boasted a large Jewish membership, some of whom came from inter-linked Jewish communities that cut across the border). The paper offers a broad framework for the study of the alliance between the two parties but focuses on moments where the relationship had a major role such as the communist-supported Iraqi revolution of 1958 which helped Tudeh organize a base in Baghdad; the anti-communist Iraqi coup of 1963 which led to Tudeh networks in the USSR helping to smuggle Iraqi communists to safety; and the 1980 when Iranian and Iraqi communists stood together even as their two nations became engaged in a deadly war that was a major disappointment for the proponents of Third World solidarity. The paper bases itself on archival material and printed press from Iraq, Iran, US and the UK. Defying the Moscow-focused narratives on communist history, it will attempt to show relations between the communist parties in the global south could at least be as important as their ties to the ‘Big Brother’ in Moscow.