The article examines the growing radicalization of the Marxist anti-Islamic discourse in the USSR as a case-study of "Soviet Orientalism". To which of Marx's five socio-economic formations should Muslim society be assigned? During the relatively pluralistic period of the New Economic Policy (1921-1927) Marxist scholars offered various answers. Many argued that Islam emerged from the trading community of Mecca and was trade-capitalist by nature (M. Reisner, E. Beliaev, L. Klimovich). Others held that Islam reflected the interests of the agriculturalists of Medina (M. Tomara), or of the Bedouin nomads (V. Ditiakin, S. Asfendiarov); and some even detected communist elements in Islam (Z. and D. Navshirvanov). All authors found support in the Qur'ān and works of Western Orientalists. By the late 1920s Marx' and Engels' scattered statements on Islam became central in the discourse, and in 1930 Liutsian Klimovich rejected the Qur'ān altogether by arguing that the book, as well as Muhammad himself, were mere inventions of later times. By the end of the Cultural Revolution (1929-1931) it was finally "established" that Islam was "feudal" in character, and critical studies of Islam became impossible for decades. The "feudal" interpretation legitimized the Soviet attack on Islam and Muslim societies at that time; but also many of the Marxist writers on Islam perished in Stalin's Terror. We suggest that the harsh polemics the authors directed against each other in the discourse contributed to their later repression. By lending itself to the interests of the totalitarian state, Soviet Marxist Islamology committed suicide—the ultimate form of "Orientalism".