In Family Court, a paternity petition generally is used to establish paternity for a father, such as a biological father. An order establishing paternity is called an order of filiation. In these types of cases, if you and the other parent do not know or agree on who the father of a child is, the court may order a DNA test.

When a child is born to parents who are not married to each other, the biological father is not considered the child's legal parent unless the father has signed an "Acknowledgment of Paternity" (usually done at the hospital at the time of the child's birth) declaring himself to be the child's father, or an "order of filiation" has been entered, which is a court order that declares that person to be the legal father.

If an unmarried couple doesn't sign an Acknowledgment of Paternity form or a mother was married to someone who is not the biological father, a paternity case can be started in Family Court for an Order of Filiation. An Order of Filiation is a court order that names a man as the father of a child.

The state or condition of a father; the relationship of a father. English and U.S. Common Law have recognized the importance of establishing the paternity of children. In the United States, a child born outside a legal marriage relationship will lose Child Support and inheritance rights if the fatherhood of the child is not legally established.