Since the 1990s, Lean production (LP) has been widely used in manufacturing for cost reduction and quality improvement. Meanwhile, in the last decade, Industry 4.0 (I-4.0) technologies have been incorporated into manufacturing, enabling Cyber-physical Systems (CPS), the Internet of Things (IoT), Augmented Reality (AR), Sensor technology, and others. Due to the advancement of I-4.0, researchers worldwide have been investigating whether there is any complementary effect of Lean and I-4.0 on operational performance, developing a strategic framework to integrate both paradigms successfully. In this context, this study was conducted using a systematic literature review (SLR) methodology to review the synergistic relationship between Lean and I-4.0, their integration framework, and the critical factors behind the sustainability of that integration. This study reviewed 41 journal articles and conference proceedings that met the SLR criteria. These articles were available in ScienceDirect, Taylor & Francis, and Emerald Insight databases and were published between 2011 and 2022. The number of publications from 2019 to 2022 follows an upward tendency, referring to an emerging research field of integrating I-4.0 into the LP system. The primary contribution of this study is investigating the relationship and integration framework of Lean and I-4.0 and the successful driving factors of integrating I-4.0 into the LP system. (c) 2023 The Authors. Published by ELSEVIER Ltd. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0)