Nassau grouper (Epinephelus striatus) were historically one of the most important shallow water fisheries in the Caribbean, yet now are rarely taken. Although normally solitary, during the winter full moon Nassau grouper attend aggregations at spawning site to reproduce. Now, however, there are only a handful of known Nassau grouper aggregations with more than 1,000 fish left in the Caribbean. Why has the species declined so precipitously, and what can be done to reverse the trend? I will discuss recent and ongoing research into the behavior and ecology of Nassau grouper, and highlight the conservation implications of this work. I will also discuss critical research needs in the ongoing effort to identify prudent conservation measures for this species.