Mr. Schlesinger opened his firm in Libertyville, Lake County, Illinois in 1986, devoting the practice exclusively to family law matters including divorce, alimony, custody, support, paternity, and adoption cases. He has handled cases in Cook and Lake counties in the trial courts and the appellate court. Mr. Schlesinger is a 25+year member of the American Academy of Matrimonial Lawyers. He has served on its Admissions Committee, its Board of Directors, and as Vice President.

In June 2004, Gary Schlesinger began serving a three year term as a member of the Assembly of the Illinois State Bar Asssociation, representing the lawyers in Lake County. In 2007, Gary was reelected to a second 3 year term.

Most recently Gary Schlesinger has been appointed by the President of the Illinois State Bar Association as a liaison with the attorney registration and disciplinary commission of the Illinois Supreme Court.

Mr. Schlesinger has also been appointed to the governing body of the Illinois State Bar Association Family Law Section, called the Family Law Section council.  The council will review and recommend all family law legislation pending in the Illinois legislature, publish a newsletter, and put on seminars.