Osmotic membrane bioreactor (OMBR) is an emerging technology that integrating a forward osmosis (FO) process into a membrane bioreactor (MBR). This technology has been gaining increasing popularity in wastewater treatment and reclamation due to its excellent product water quality, low fouling tendency and high fouling reversibility over conventional MBRs. In past decade especially the last 3 years, novel insights and significant advancements have been achieved in many aspects of OMBR accompanied with greatly increased number of published papers. This paper attempts to critically review the recent developments in OMBRs and to present a clear outline for further studies. Firstly, OMBR fundamentals including its configuration and FO process are presented. Subsequently, performance of OMBRs is summarized and compared to conventional MBRs. Additionally, mechanisms, impacts and mitigations of salt accumulation and membrane fouling related to the core challenge of low water flux in OMBRs are addressed. Finally, future research prospects are discussed in order to further improve OMBR technology and drive it from laboratory research to real practical applications.