Widespread concern about the presumed global-scale deterioration of coral reefs mandates the need for documented case histories of the world's coral reefs. To meet this need, the Colloquium organizers assembled a series of case histories. Some 50 case histories from 22 different countries were selected as examples of the health, hazards and history of reefs. These case histories were used as the basis for critical review by coral reef scientists at a three- day Colloquium in June 1993. Based on these case histories, the Colloquium addressed several key questions: What is the geographical extent of coral reef deterioration or under stress? How will the expected global warming influence reefs? How can natural vs. anthropogenic-induced changes be identified? Does sea level history explain some of the variations in the vigor of reef communities? What is the impact of oil spills on coral reefs? How do excess nutrients from land-runoff affect reefs? Immediately following the Colloquium, an open two-day Forum with keynote speakers presented the results of this review to the public. Selected case histories, their review and recommendations from the Colloquium and Forum will be published in the University of Miami Serial Publication.