In a medical emergency, a delirious patient can be treated without consent under the common law doctrine of implied consent, but in nonemergency situations legal guidelines are less clear. Implied consent may be extended if measures are taken to safeguard the patient's interests; these include involving family members in the treatment decision, obtaining a second clinical opinion, and seeking administrative consultation. Time permitting, if there are several alternative treatments and the risk of intervention is great, a court should appoint a temporary guardian. Documentation of the course of action is strongly recommended. The authors discuss the appropriateness of diagnostic procedures and the use of antipsychotic drugs to treat combative delirious patients. Legal precedents are offered and clinical examples given.