As the spread and impact of the invasive Indo-Pacific red lionfish explodes in the western Atlantic region, REEF continues to take a lead in addressing this complex environmental issue. In addition to extensive outreach and education efforts, REEF staff is involved in several field research projects to study the ecological impact of this voracious predator. REEF is also coordinating regional response efforts. In partnership with the International Coral Reef Initiative (ICRI), NOAA, Mexico and France, REEF helped fund and organize the first Regional Lionfish Strategy Workshop in August. The two day workshop brought together more than 40 key Marine Protected Area and fisheries managers from 17 countries and territories in the Caribbean to discuss control strategies, initiate cooperative efforts to address the invasion, and begin development of a best practices document. Participants shared stories on successes, challenges, and needs for responding to this highly invasive species. Many of those participating have worked with REEF over the last two years to initiate training and lionfish culling programs. A report from the workshop and initial steps on developing the lionfish best practices manual will be presented at the annual conference of the Gulf and Caribbean Fisheries Institute this Fall.