Abstract We have previously established that the growth mode for Ag on Fe(110) is Stranski-Krastanov with Ag islands growing on top of two intermediate Ag layers. In the present study, patches of Ag are deposited on Fe(110) at room temperature and subsequently annealed. Quantitative information is obtained by monitoring the expansion of these patches as a function of time using biased secondary electron imaging. The experiments indicate that the first Ag monolayer (ML) expands via surface diffusion of adatoms produced by the dissociation of the islands and the second ML. A kinetic model is developed to explain the expansion (and contraction) of these layers and to extract related atomic energies. The effective activation energy for surface diffusion is similar in value to that obtained for Ag W(110) .