In-Line Inspection (ILI) tools are most widely used to inspect pipeline structures and employ standard procedures of pipeline inspection even today. The major challenge of operator companies is to inspect non-piggable pipelines, due to their limited access. Most In-Line Inspection (ILI) methods, such as pigging, require a launcher/receiver and require operations to stop for the inspection procedure to take place. In recent years, a non-contact Magnetic Tomography Method (MTM) has been introduced as a non-intrusive method, which is able to inspect ferrous magnetic pipelines without contact. MTM technology was originally used as a conventional onshore pipeline inspection tool. After several years, an innovative research and development program on the technology, by PETRONAS Carigali Sdn Bhd and LLC R&DC Transkor-K, introduced the AQUA MTM Technology; which is capable of inspecting subsea pipelines without contact. Now, this technology is commercially available for the oil and gas industry. This paper briefly discusses the application of the non-contact magnetic tomography method for subsea pipelines Keywords- Non-contact Magnetic Tomography Method (MTM), inspection, pipelines, In-line inspection, applications, onshore, offshore.