Si–Ge–Mo composites are prepared using an RF/DC magnetron sputtering method, and their potential use as anode materials for rechargeable lithium-ion batteries is investigated. The Si–Ge–Mo composite films present an amorphous structure. The reaction mechanism of the Si–Ge–Mo with Li is investigated by various analytical techniques. The fabricated Si0.41Ge0.34Mo0.25 composite film shows excellent electrochemical properties, including a high energy density (1st charge: 1193mAhg−1), long cycleability (ca. 870mAhg−1 over 100 cycles), and good initial Coulombic efficiency (ca. 96%). Additionally, when coupled with a LiCoO2 cathode, the Si0.55Ge0.22Mo0.23 composite electrode used as an anode shows excellent cycleability with a high energy density. The excellent electrochemical properties demonstrated by the Si–Ge–Mo composite film electrode confirm its potential as an alternative anode material for lithium-ion batteries.