Embryogenesis and larval development were documented in 19 species of hermatypic scleractinians which release gametes during the summer coral spawning season oil the Great Barrier Reef. Cleavage of fertilized eggs began approximately 2 h after spawning in all species, and gave rise to blastulae after 7-10 h. Endoderm formation in Platygyra sinensis was by invagination, and this appeared to occur ill all species studied. All species observed at 36 h after spawning Were mobile and full mobility was reached by 48 h. Settlement of planulae placed in aquaria occurred between 4 and 7 days after fertilization. These results suggest that larval corals produced by most gamete-releasing coral species are likely to be dispersed away from the parent reef.