High Pressure piping is often an area which receives less attention during the lifetime of a urea plant; there is no logical reason for this. Paying not enough attention or wrong inspection/repair procedures can lead to catastrophic incidents. This paper will provide an overview of the various corrosion phenomena occurring in High Pressure Piping systems in urea plants. It will elaborate the corrosion phenomena from the inside (process side) as well as the outside (atmospheric corrosion / corrosion under insulation). Many incidents have illustrated the risks involved and have shown the importance to pay sufficient attention to this part of the urea plant.