Published information provides scientific evidence that traditional, involuntary restraint techniques of research non-human primates are intrinsically a source of distress resulting from fear. It has been documented that common methods of enforced restraint result in significantly increased adrenal activity as well as significant changes in a variety of other physiological parameters. There is no scientific evidence that the animals adequately habituate to involuntary restraint. Numerous reports have been published demonstrating that non-human primates can readily be trained to cooperate rather than resist during common handling procedures such as capture, venipuncture, injection and veterinary examination. Cooperative animals fail to show behavioural and physiological signs of distress. It was concluded that the advantages of training techniques over traditional restraint techniques will have to be explored more extensively in the future for the sake of research subjects and scientific methodology.