This is the first report of disease in azooxanthellate scleractinian corals, associated with a powerful invasive species of the Brazilian coast, Tubastraea tagusensis. . In this context, we sought to describe this pioneering disease and analyze its progressive stages. We verified how the host's resident microbiome reacted to the disease progression, despite the imbalance of the community due to tissue necrosis, and proposed potential pathogens as causative agents.