In this research, it was carried out an analysis of the evolution of the underground pipelines structural reliability using five corrosion growth rate distributions. These distributions were based on: a single value recommended by NACE, linear growth model, nonlinear growth model taking into account the soil characteristics and Markov chains. The results obtained were compared among them in order to show that to take into consideration age, depth and time evolution of corrosion active defects are critical to estimate the pipeline reliability.