With a solid-on-solid model, we show how adsorbates can induce surface roughening. Roughened surfaces exhibit pits and regrowth structures that have characteristic patterns that depend directly on the adsorbate coverage and on the strength and type of involved interactions. Monte Carlo simulations were used to explore the consequences of adsorbate-adsorbate repulsion and two types of adsorbate-substrate interactions that lead to roughening, (C) 2004 Elsevier B.V. All rights reserved.