court appointed special advocates (casa) is an organization in the united states. casa supports and promotes advocates for abused or neglected children which are appointed by courts of law. the purpose is to provide children with a safe and healthy living environment in permanent homes. the program is similar to, but in most states is not the same as a legal guardian ("guardians ad litem"). according to national casa, today there are more than 77,000 advocates. they serve in 933 state and local program offices nationwide. because of these volunteers, 233,000 children have been assisted through casa services.