The finite element calculations in this letter present a detailed picture of tensile stress evolution during island coalescence in polycrystalline films. Earlier models suggest that these stresses are produced only when islands initially coalesce. In contrast, our model predicts that stress evolution is an inherent part of the growth process when two neighboring surfaces grow together to form a grain boundary. This view of coalescence stress is also consistent with experimental observations. (C) 2002 American Institute of Physics.