The aim of this master thesis is to highlight the importance and key role of the principle of truth-seeking in civil proceedings. Determining or finding the truth depends on the quality and success of the evidence, but it also depends on the free judgment of the court. Evidence as a litigation action helps to provide an easier establishment of facts, and at the same time makes it much easier for the court to make legal and correct decisions. Therefore, it is important to conduct the presentation of evidence in a legal manner, in accordance with the provisions of the Civil Procedure Act and the rights guaranteed by the Constitution. In the proceedings, the litigants present the evidence on which their request is based, while the court decides with its free judgment which will be taken into account. The Law on Civil Procedure determines the admissible evidence, namely the investigation, documents, witnesses, experts and the hearing of the parties. The Law on Amendments to the Law on Civil Procedure from July 2022 is implemented in civil proceedings against illegal evidence. In the end, the court determines with a free evaluation which facts have been proven in the procedure and will evaluate them according to its own conviction when making a decision.