As the water demand increases continuously, large capacities of desalination plant are added every year to meet freshwater demand. The higher carbon footprint of desalination raises concern on global climate change. The integration of desalination and renewable energy source could mitigate this water-energy nexus. Membrane distillation (MD) is a non-isothermal desalination process in which the low-grade heat is used as the driving force. Many researchers have tried to integrate solar energy and MD for sustainable water desalination. This article presents a comprehensive review of solar MD desalination to understand its current state of development. Solar powered MD systems have been investigated for last few decades. However, its commercialization is very limited due to low flux, high specific energy consumption and large collector area requirement. Further, this review presents the recent developments in MD membrane, innovative MD modules and the importance of optimization, which was able to improve the performance of solar MD. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.