Canine aggression directed to human beings is a common presenting complaint and requires attention to safety issues and behavior modification to minimize the risks of future aggression. Dogs may bite familiar people, including family members, or unfamiliar people for a variety of reasons. Anxiety plays an important role in aggression regardless of its target or circumstances. Effective management of aggression may include education and safety counseling for owners, lifestyle changes for dogs and owners, avoidance of provocations when possible, and behavior modification to minimize the risk of future bites. Drug therapy may be indicated to facilitate behavior modification or to reduce reactivity in the dog.