The applicable rules of evidence often are a determining factor in cross-border proceedings. For the first time, the EU-regulations "Rome I" and "Rome II" have established uniform conflict-of-law-rules for contractual and non-contractual obligations, including provisions regarding the law of evidence. The thesis first comprehensively analyses these provisions in consideration of the previous legal situation under unharmonized national law and the special nature of the international law of evidence as an area of law at the interface of international private and international procedure law. On this basis, then all rules of evidence with practical relevance are examined in terms of the applicable law with a special focus on the forensic practice. Finally, specific recommendations are made regarding a revision of the international law of evidence.