Most lawyers do their most to provide the best representation possible. However, every so often lawyers do not act properly or make serious mistakes, and in those cases their clients can file a complaint with the entity responsible for overseeing the practice of law in their state. It should be noted that this is different than filing a legal malpractice lawsuit, which is a court action to recover damages based on an attorney's mistake or misconduct in a legal matter.
Each state has a different organization that reviews complaints against lawyers. In many states, a division of the courts handles these complaints. This is typically referred to as the disciplinary board. Some states rely on their state bar associations to discipline their attorneys. You can find out where to send attorney complaints by looking at your state court system's website. If they review complaints against attorneys, there will be a link with instructions on how to file.
Although the technicalities of every state's complaint process are slightly different, the overarching procedure is similar. First, an attorney or panel of attorneys will review the complaint and decide whether the complaint is worth investigating. Many people file complaints against their lawyers for the wrong reasons, and the disciplinary board does not want to waste time and money on meritless complaints.
If the complaint is sustained, the disciplinary board will begin its investigation. Sometimes the lawyer will be required to appear at a hearing and answer questions about the incident that prompted the complaint. If the complaint is found to be true, the disciplinary board can fine the attorney, force the attorney to attend classes or perform community service, or take away the attorney's license. The disciplinary board typically does not give the person who complained about the attorney any money. It usually serves only to admonish, suspend, or disbar attorneys who break the rules governing the practice of law.
For attorneys, a disciplinary action is very serious as it can directly affect their ability to earn a living. It may be best to first try and resolve any dispute you have with the attorney on your own. Also note that if you have a legal matter pending and you file a complaint against your lawyer, that lawyer must stop representing you in most states, so it may be a good idea to have another attorney lined up to take over in advance.
See FindLaw's Guide to Hiring an Attorney for more information.