The author discusses the problem of the abuse of authority by a professional counsel in civil proceedings. Such abuse should be specifically understood. The premises for the abuse of authority by a professional counsel embrace acting within the limits of authority set by the scope of the power of attorney, taking procedural steps against the real or hypothetical will of the principal provided that acting in accordance with his will does not violate the rules of professional conduct of the counsel. The lack of due diligence of a professional counsel in litigation is not a premise for the abuse of authority but due diligence affects his liability for damages. Abuse of authority is counsel’s failure to maintain due diligence.