The fear of personal liability can seriously erode the necessary confidence of police officers and their willingness to act. Even worse, police officers who have an unrealistic or exaggerated fear of personal liability may become overly timid or indecisive and fail to arrest or search, to the detriment of the public's interest in effective and aggressive law enforcement. In order to accurately assess their potential exposure to personal liability, law enforcement officials must understand the constitutional law that governs their conduct. They must also understand the protection of qualified immunity that shields officers from personal liability for unconstitutional law enforcement activity that is deemed objectively reasonable. Recent court decisions that clarify the extent of protection from personal liability offered by the qualified immunity defense are discussed. It is concluded that the qualified immunity defense does not excuse clearly unconstitutional or offensive police misconduct, but it does offer generous protection to conscientious police officers who make objectively reasonable mistakes. 17 references.