Invasive alien species (IAS) is a scourge that gnaws away at biodiversity, the environment as a whole, and the socioeconomic fabric of countries. In Morocco, nearly 150 IAS have been inventoried and argued, and it is sincerely believed that this number is well below the actual total number of IAS introduced into the country, which suggests other scientific investigations, both on the ground and in the laboratory, to be able to identify them. These IAS cause damage, sometimes catastrophic. Virtually all environments suffer: ecosystems, landscapes, the agro‐ecosystem, the forest ecosystem, wetlands, and the marine and coastal environment. The country's economy, its social stability, as well as human and animal health are also concerned. In agriculture and aquaculture, vital and strategic (food security, jobs, rural economy), IAS pose a real threat to grain farming, arboriculture, seaweed farming, and so on, and almost all species of food interest are threatened by IAS, accidentally or deliberately introduced to the point where yield, of cereal for example, has dropped by 98% in some areas of the country. The reduction in yield concerns not only cultivated plants but also farmed animals (sheep flocks, goats, birds, bees, etc.) because of their toxicity, their aggressiveness, or their competitiveness. The Moroccan forest, which is strategic for the country's overall ecological balance and for its rural economy, also suffers from IAS, in particular its heritage species such as the Atlas cedar. Wetlands that have experienced fish introductions since the beginning of the last century have been greatly affected by these exotic species to the point that, in the early years of introduction, native forms such as pallary trout have been exterminated. The marine and coastal environment, despite its buffering capacity, is beginning to feel the weight of the threat of IAS introduced mainly for aquaculture reasons. The information concerning this environment remains very fragmentary given the insufficient human and material resources available for exploration of this area, particularly for ballast water and bio‐soiling. The little information that exists, however, shows a negative effect of introduced species on native ones. Silverleaf nightshade (in Morocco, morelle jaune) and the pine processionary are also the origin of respiratory or allergic diseases, and the tiger mosquito could be the origin of many more serious diseases. The fight against IAS remains punctual, often mechanical, without a targeted strategy; and the main monitoring instrument remains the establishment of the National Office for the Health Security of Food Products (ONSSA), whose main task is the control of transit, at each point of entry into the national territory, of plants, seeds, animals, and biological material potentially harmful to the environment or health in the country.