In the Moroccan Atlas, sedimentary deposits provide important data on reef events that characterize the Jurassic period. Recent work allows us to enhance knowledge of the Jurassic reefs in the Atlas, in particular their age, character and palaeogeographic distribution. Numerous localities with sponge-microbial mud mounds, coral reefs, and lithiotid bioherms are recorded from the Middle and High Atlas regions. These different biogenic constructions occupy different palaeogeographic settings: on the top of tilted blocks within the basin center; in slightly deeper positions, at the basin platform junction; and on adjacent platforms in the middle of the coastal area. The main episodes of reef building span nearly 30 million years, as follows: (1) Sinemurian, (2) early Pliensbachian, (3) late Toarcian, (4) Aalenian-early Bajocian (pars), and (5) late Bajocian. These five distinct reef events can be linked with general fluctuations of sea level and tectonism, and have palaeoclimatic implications. (C) 2018 Elsevier Ireland Ltd Elsevier B.V. and Nanjing Institute of Geology and Palaeontology, CAS. Published by Elsevier B.V. All rights reserved.