Natural gas is an indispensable energy resource of today. It is transported from production centers to the consumption areas extensively using underwater pipelines. Several reasons such as aging, internal and external corrosion, flaws, seabed tectonic movements, fatigue cracking, pitting and ship anchors are responsible for rupturing underwater natural gas pipelines (UNGPs). Therefore, pinpointing the leakages in the UNGPs are important to prevent wasting this energy resource. This study introduces a method, which uses passive acoustic based received signal strength difference (RSSD) technique, to localize the leakages in the UNGPs. Considering a real life UNGP, the performance of the proposed method is scrutinized by simulations. The positioning error of the proposed method is compared with a received signal strength (RSS) technique based method, which is considered as a benchmark. The RSS technique demands leakage (source) strength information but it may not be possible to know the leakage strength instantly. However, RSSD techniques does not need leakage strength information. It is shown that leakage localization with small positioning errors can be performed via the proposed method. (C) 2019 Elsevier Ltd. All rights reserved.