A simple model is proposed which predicts the composition of sputtered multicomponent thin films. The model is applied to such problems as alloy sputtering, gas incorporation into thin films, and compound formation. Several practical systems are considered such as the sputtering of Gd3Fe5and Ni4Fe alloys and the incorporation of argon, oxygen, and nitrogen into tungsten films. The results of these studies suggest that the film composition is a strong function of vapor pressure, sputtering rate, atomic size, system geometry, sticking probabilities, and sputtering coefficients.