Wild mammals sometimes need to be restrained for conservation purposes. Game rangers, wildlife managers, field biologists and wildlife veterinarians need to be fully conversant with a wide array of environmental and biological variables when using chemical restraint on wild mammals. In order to minimize risks to subject animals, they also need to be able to react appropriately using the correct equipment with sufficient skill to deal with anything that can go wrong. The importance of thorough background research and planning before going into the field cannot be overemphasized. The physiological results of immobilization drugs delivered by dart depend on dosages, the success of dart placement and drug delivery in good muscle, as well as the physiological state of the animals prior to and during anaesthetic induction. This paper describes the essential components of a planning and monitoring protocol for chemically restraining terrestrial mammals under field conditions.