If there is a paternity issue in a family law case that generally means there is some question concerning who the biological father is. Usually people need to disestablish paternity of one man and establish paternity of another man. For instance, the law presumes that the husband is the father. Therefore, if a child is born to a married woman, her husband is legally the father - even if it was absolutely impossible, i.e. The husband was incarcerated and they hadn't seen each other for 10 years. In these situations, the husband is usually disestablished as part of the divorce case, and the biological father is established. Questions of paternity come up in many other situations. If this is an issue in your case, you are urged to consult a lawyer or call the Family Law Helpline.