Intertidal microbial mats are complex, highly structured ecosystems that play a crucial role in marine coastal environments. While there is extensive research on microbial mats and communities across an extensive range of habitats (intertidal and subtidal, hypersaline and arid coasts and lakes, freshwater lakes, thermal pools and the polar regions) and within laboratory settings, coastal microbial mats are particularly interesting as their ecosystem services are largely driven by daily, monthly and seasonal conditions. Under suitable conditions these mats serve a series of key ecological roles including primary production, stabilization, nitrogen fixation, carbon sequestration, as well as being source material within trophic food webs. However, these microbial systems are under increasing threat from the impacts of climate change, and more immediately, coastal development and urbanisation. In order to present a concise picture of the ecological values and threat to these ecosystems which can be useful in coastal management, we conducted a review highlighting global research on intertidal microbial mats, as well as further impacts of their disturbance through climate and coastal changes.