Despite the fact that the Roman state no longer exists, Roman law still lives among us. The Roman state left a very high-quality legal foundation, and Roman law became the basis of the law of numeorus states. The Romans were aware of the fact that is not enough to prescribe imperative and prohibitive norms, but also to provide an authority that will apply them. In accordance with the dynamism of society, changes were introduced, and they went from a lay judge, a non-professional and a person without legal knowledge to a judge who was a legal expert and expert – for whom this was his main job. Certain qualifications were required without which one could not become a judge. They also knew the responsability in cases of corruption of judges or avoidance of judicial duties. The period of the Roman Empire was the closest to the understandings of judiciary as we know today in contemporary Croatian legislation. The distance of the city of Rome and the large territory of the Roman state resulted in the emergence of arbitration, which was a way of avoiding regular court cases. Arbitrations were faster and more simple. The Romans knew arbitration boni viri and arbitration ex compromisso, administrative arbitrations were also mentioned. The Croatian legal system knows ad hoc and institutional arbitration. It is based on an arbitration agreement which may be in the form of an arbitration clause or a separate agreement. The decision regarding the arbitration procedure is called arbitration award, and the legal remedy against it - is a lawsuit for annulment of the arbitration award. We see arbitration, both in the period of Roman State and in the modern Croatian legislation, as a high-quality, out-of-court settlement of disputes