The topic of paper work is damage and rehabilitation of reinforced columns. The paper work is divided into six basic sections. The first section speaks in general about reinforcedconcrete structures and basic assumptions for analitic methods. There is also defined what reinforced concrete column is. The following section describes which impacts cause damage to reinforced concrete structures and how. Every kind of degradation process is described in particular. The third part speaks about the types of damage on the columns, which parts of the columns may be damaged (concrete or reinforcement), and how damages can look like. Here is also described the size of the construction damage which is permitted under the applicable regulations. In the fourth chapter, two experiments on determining the bearing capacity of reinforced concrete columns of the damaged round and rectangular cross section are described. The results were also compared. The last two chapters talk about methods of repairing the damage of reinforced concrete columns and preventing the occurrence of significant damage. In this section is calculated exapmle of strengthening.