Weasels, stoats, polecats, pine martens and the American mink are small mustelids that may occasionally be presented to the veterinary surgery. The most common reason for presentation of small mustelids is trauma. Bite wounds from cats or dogs are relatively common; snaring or trapping injuries are also seen. This chapter covers: ecology and biology; anatomy and physiology; capture, handling and transportation; clinical assessment; first aid and hospitalization; anaesthesia and analgesia; specific conditions; therapeutics; husbandry; rearing of mustelid kits; rehabilitation and release; and legal considerations.