This paper summarizes the finding from the 2002 REEF Grouper Moon Project, which documented the characteristics of a newly discovered Nassau grouper spawning aggregation. At its peak, over 5,000 Nassau grouper were present at the site. Significant contributions include the visual and video documentation of four nights of spawning of Nassau grouper, the description of crepuscular and lunar movements and color phase shifts in the grouper, and the documentation of courtship/spawning behavior in ten additional species. This paper was also presented at the 2002 Gulf and Caribbean Fisheries Institute Meeting.