Acoustic Emission (AE) technique is considered as a Non-Destructive Testing (NDT) method used in monitoring and in the inspection of structural flaws. The AE signal is the generation of the rapid release of strain energy that usually occurs within the material during crack propagation or burst of gas leakage. One of the applications of this method is to monitor possible flaws that might take place specifically in pipeline installations. This could also be used to locate the leak source and effectively characterize the development of defects such as deformation, corrosion, cracks, etc. Thus, the acoustic emission signal is used to analyze the attenuation of elastic waves derived from the pipeline leak because according to study the AE amplitude is proportional to the leak energy. From among the leak detection methods, the AE technique can observe defect in real time situation and it is very sensitive to any form of flaws. Finally, its application is considered as an efficient and cost-effective testing process among other relevant methods.