The main threat facing this species is habitat loss as a result of logging for hardwoods, exploitation for charcoal production and fuel wood, livestock grazing, agriculture and mining of limestone. In the Dominican Republic around 35% of suitable habitat has been totally lost; of the remaining habitat, 75% is disturbed and the situation is much worse in Haiti (2). Other threats include predation by dogs, cats, pigs, and mongooses, and illegal hunting by humans for food is a very serious problem in parts of Haiti, a country mired in poverty (2) (4). International trade in wild rhinoceros iguanas has been controlled since 1987 in the Dominican Republic, but not in Haiti (2).
Introduced exotic species pose the most serious threat to the subspecies on Mona Island, which has evolved in the near absence of predators and is therefore ill-equipped to cope with the dangers they now pose. In particular, the combined effect of pigs consuming eggs and cats preying on young has resulted in the present scarcity of juveniles on the island. Feral goats may also be having a damaging impact by gathering in sinkhole depressions on Mona's plateau where the iguana nests, and also through intense browsing pressure affecting the vegetation of the island. Although there are no permanent settlements on the island, Mona attracts many recreational pursuits, including camping, fishing, swimming, scuba diving, beach combing, exploring, and hunting. Most of these activities are concentrated along the island's sandy coastal terraces and within sinkhole depressions, areas of critical importance for iguana nesting. An additional recent concern is the emergence of an unidentified disease or parasite that causes blindness in the iguana, which in turn appears to affect the iguana’s ability to feed (2).