The art of Marcel Duchamp is notable for its thematic repetition, notably that of Eros. The infinity symbol, ∞, is a more specific throughline, appearing in works by or associated with Duchamp from 1921 onwards. The concept of infinity has three primary applications: the mathematical, the physical, and the metaphysical. With respect to Duchamp, the authors analyse mathematical applications via the Möbius strip and Klein bottle. They investigate physical manifestations of infinity via Duchamp’s La Bagarre d’Austerlitz (1921) and Anémic Cinéma (1926). The infinity symbols in a diagram representing Adam and Eve developed with Georges Bataille, published in Duchamp’s satirical journal ‘Mémento Universel Da Costa’ (1949), serve to clarify metaphysical aspects. For Marcel Duchamp, creativity was Erotism, a psychological and spiritual quest for continuity, infinity.