Neuroleptanalgesia refers to the combination of a potent sedative analgesic agent (an opioid) and a tranquillizer. Studies evaluating neuroleptanalgesia in nonhuman primates are absent, but it has been used extensively and for many years in numerous laboratory animal species including primates (Marsboom et al., 1963). There are no recent reports of the use of commercially available neuroleptanalgesic combinations (fentanyl/fluanisone, fentanyl/droperidol) in primates, although they have been used for immobilization and to produce light surgical anesthesia. Combinations of opioids and benzodiazepines, delivered by continuous infusion, can provide surgical anesthesia in macaques and marmosets (unpublished data from author’s laboratory).