In zoo and laboratory colonies of marmosets and tamarins (Callitrichidae) there has been an increasing need to adopt breeding control methods. In zoos, this need has been driven by a growth in populations. In laboratories, increased interest in control options has followed from the requirement to improve welfare by housing potential breeding animals together. Progestagen-containing contraceptive implants or depot-injections, prostaglandin injection regimes, vasectomy and various group-management methods have been used to control reproduction in marmoset and tamarin colonies. There is a need for advances in control techniques suitable for use in zoos. In the meantime, a policy of selective euthanasia or the use of vasectomy are recommended as control methods. In laboratories, although improved control methods are required, a number of techniques have been found to be satisfactory. When there are surplus marmosets and tamarins, the alternatives for their utilization include movement to other colonies, use for studies within zoos or in laboratories, sale to private keepers or euthanasia. Selling these animals privately is not recommended, except in exceptional circumstances. The preferred control option will differ in each circumstance and guidance is given in this paper.