Joint custody of minor children is controversial. Both parents, after a divorce, are determined to be fit custodians of their children and they share custody responsibilities. Joint custody is perceived as the least disruptive method of custody, for it provides children with access to both parents. However, joint custody requires cooperation between the parents in managing the divorced family's life. The interspousal conflict that caused the divorce often surfaces to prevent the former spouses from cooperating in carrying out their joint custody responsibilities in ways that are in their children's best interests. The appointment of a guardian ad litem for the children provides a way for families with joint custody arrangements to cooperate in child rearing. The guardian ad litem acts as a mediator of family conflicts and also monitors the child caring arrangement. While there may be problems with the definition of the role of the guardian ad litem, they can be solved, in part, by drawing up specific guidelines delineating the rights, powers, and scope of authority of guardians ad litem, parents, and children within the joint custody mediation system. The guidelines can be incorporated into the joint custody final decree or may be used by the court for general reference. A sample set of guidelines is included. 357 footnotes.