Corrosion-induced deterioration of reinforced concrete structures results in premature concrete cracking and spalling, leading to ultimate structural collapse. In practice concrete crack width is one of the most important criteria for the assessment of the serviceability of concrete structures. It is therefore desirable to have knowledge of the growth of the crack width over time so that better-informed decisions can be made concerning the repairs due to concrete cracking. Literature review shows that little research has been undertaken on numerical prediction of concrete crack width. The intention of this study was to develop a numerical method to predict corrosion-induced concrete cracking and crack width for corrosion-affected concrete structures. A cohesive crack model for concrete is presented and direct tension tests on concrete are carried out to determine accurate concrete properties. Worked examples show that the numerical results are in good agreement with the analytical results. It can be concluded that the numerical method developed in the paper can predict corrosion-induced concrete cracking and crack width with reasonable accuracy.