Reinforced concrete structures have the potential to be very durable and capable of withstanding a diversity of adverse environmental conditions. However, failures in structures still occur as a result of variety of defects among which premature reinforcement corrosion is one.rnIn the case of concrete structures, the main effect of the reinforcement corrosion is its section decreases due to the corroding process. Reduction of reinforcement thickness then leads to loss of mechanical strength and structural failure or breakdown.rnIn this thesis, the chemistry of corrosion in concrete is briefed. The damages caused by corrosion of steel in concrete, corrosion detection measurement in built structures and corrosion consideration in developed countries are also discussed.rnSince much attention is not being given to corrosion effect in Ethiopia construction industry, some sample pictures are collected from construction sites and is attempted to show the corrosion consideration in our country.rnPoor construction methods and workmanship could attribute to the failure of structures. The poor construction methods and workmanship is caused due to negligence and inadequate quality control at construction sites. The study discloses that labor and money could be saved by means of repair and rehabilitation; and serious accidents could be avoided if the corrosion of reinforcements is well understood, detected and monitored at early stage.rnKey words: Corrosion, Reinforcing steel, Repair, Rehabilitation and failure