Abstract: Corrosion of steel reinforcement is one of the most significant causes of deterioration of reinforced concrete structures. At present, most reliability studies of reinforced concrete structures do not consider the effects of corrosion. In this paper, we present a reliability-based approach to the assessment of concrete structures with corroded reinforcement. First, models for reinforcement corrosion in atmosphere and chloride environment are analyzed. Secondly, it is assumed that corrosion will lead to a reduction in reinforcement cross-sectional area and a reduction in bond strength. A stochastic model for resistance of concrete structures with corroded reinforcement is proposed. The reliability of reinforced concrete structures in atmosphere and chloride environment is estimated in terms of the reliability index using the first-order reliability method. The present approach, which is demonstrated in two examples, can be used to assess reliability of concrete structures with corroded reinforcement.