Harmful Algae Blooms (HAB) have been documented for at least fifty years in Latin America and the Caribbean (LAC), however, their impacts at social, ecological and economic levels are still little known. To contribute to the impact assessment of HABs in LAC region, the available information in HAEDAT, OBIS, CAREC, and CARPHA databases, and scientific literature was analyzed. This historical analysis allows identification of the main syndromes and causal organisms. Considering the existence of two regional working groups of the Intergovernmental Oceanographic Commission (IOC): Algas Nocivas del Caribe (ANCA) and Floraciones Algales Nocivas en Sudamérica (FANSA), representing Central American/Caribbean and South American countries, respectively, the analysis is presented both globally and subregional. For the FANSA region, the HAEDAT data base listed 249 records from 1970 to 2019, with a total of 1432 human intoxications, including 37 fatalities. The majority of these events comprised Paralytic Shellfish Toxins (49%), Diarrhetic Shellfish Toxins (34%), Cyanotoxins (12%) and 6 % other toxins. The total number of harmful taxa in the OBIS database includes 79 species distributed over 25 genera. The most commonly reported species are Alexandrium catenella/tamarense, Gymnodinium catenatum and the Dinophysis acuminata complex. Two new species Prorocentrum caipirignum Fraga, Menezes and Nascimento and Alexandrium fragae Branco and Menezes were newly described from Brazilian waters. In the ANCA region, HAEDAT listed 131 records from 1956 to 2018. The main problems are PSP and Ciguatera and common HAB taxa are Gambierdiscus, Gymnodinium, Pyrodinium, Alexandrium and Dinophysis. The most reported HAB forming species are Gymnodinium catenatum, Pyrodinium bahamense and Gambierdiscus spp. In recent years Margalefidinium polykrikoides blooms have become frequent, causing fish and invertebrates massive mortalities and impacts on touristic activities. In the LAC region, the greatest economic losses were produced by ichthyotoxic massive events causing salmon deaths associated to Pseudochattonella verruculosa and Alexandrium catenella in Chile and tuna deaths related to Tripos furca and Chattonella spp. in the Mexican Pacific. In the last decade, several studies in LAC have linked HAB events with local mesoscale oceanographic and atmospheric phenomena. Trends analyzed up to 2019 are related to the increasing awareness about presence of toxic species, the geographical expansion of already known species, the detection of new toxins for the region, and HAB events duration and/or impacts.