In 2009, the first lionfish (Pterois volitans/miles) was found in the Parque Nacional Arrecifes de Cozumel, in Quintana Roo, in the Mexican Caribbean; however, no official record was published about this finding but just anecdotic evidence. Early in 2010, we organized workshops to lobster diver-fishermen from the northern Yucatan Peninsula on lionfish biology and potential threat of invasion, and invited them to safely collect lionfish and record basic information. In late 2010, a fisherman captured the first lionfish for the Gulf of Mexico 130 km off the northern Yucatan coast, and 50 km off eastern Alacranes Reef National Park (ARNP). Fishermen showed positive responses; thus, more workshops were organized. From 2010 to 2011, about 445 lionfish (90 - 274 mm TL) were voluntarily collected by fishermen: 1) along the coast: El Cuyo (N = 53; size range 110 - 195 mm TL), Las Coloradas (n = 1; 186 mm TL), Río Lagartos (n = 81; 139 - 327 mm TL), San Felipe (n = 2; 255-274 mm TL), Dzilam de Bravo (n = 9; 97 - 140 mm TL) Telchac Puerto (n = 1; 155 mm TL), Progreso (n = 3; 132 - 153 mm TL) and Sisal (n = 1; 145 mm TL) and 2) off the coast: Bajos del Norte (n = 21; 83 - 217 mm TL), ARNP (n = 269; 90 - 260 mm TL), and Cayo Arenas (n = 4; 134 - 180 mm TL). This work showed that 1) local community participation on conservation is viable and 2) the lionfish invaded the northern coast of the Yucatan Peninsula. This abundance represents a pale number of lionfish since collections were only on a voluntary basis. It is necessary finding ways of collaboration with monitoring initiatives in the Mexican Caribbean and establishing others (Campeche and Veracruz) to reach decisive actions for the lionfish invasion in Mexico.