You can find a variety of small, legal monkey species that are suitable for pet ownership, such as marmosets, tamarins, capuchins and squirrel monkeys. It is extremely important when considering purchasing a monkey as a pet to research the species, price, and the requirements for its care including housing, diet, and veterinary care. Monkeys require a lifetime of specialized care, so prospective owners need to be sure to research and understand all of the implications of raising a monkey before committing to purchase one as a pet.