This study is to determine the corrosion penetration rate (CPR) of medium carbon steel in selected media and also to determine the effect of corrosion on the mechanical properties on the steel material. Weight loss experiment was used to determine the corrosion rate. Tensile test was used in conducting the mechanical properties, Ultimate tensile test (UTS), Engineering fracture stress (EFS), Ductility and Yield stress (YS). The study was investigated for a total period of 35 days with measurements made at interval of 7 days, the media used for the research are 0.5mol(H2SO4),0.5mol (HCL), Freshwater, Air and Soil. The result obtained showed that medium carbon steel has a much higher failure tendency in acidic media (H2SO4, HCL) than in the other media (Air, Freshwater and Soil). The tensile test result at the end of the analysis showed that there was a great deterioration in the mechanical properties in air. These mechanical properties such as ultimate tensile test stress, engineering fracture stress and ductility which were initially 830.130N/mm2, 1122.435 N/mm2 and 14.50% before corrosion experienced a decrease in value to 733.38 N/mm2, 830.019 N/mm2 and 10.714% respectively. Therefore, it can be concluded that medium carbon steel is an unreliable constructional material in sulphuric acid and hydrochloric acid environment, and this is as a result of its failure tendency as evidenced in their mechanical properties.