This contribution analyses issues related to the burden of proof and to the standard of proof at the ICJ. This Court functions on a private law model whereby the relevant facts have to be proven by the claimant. However, the rule on the burden of proof is softened by many legal tools which are presented in the text. A separate question is the standard of proof, i.e. the degree of plausibility, probability or near-certainty which the elements of proof much reach. This standard depends much on the underlying primary rules to be applied and is as yet underdeveloped in international jurisprudence. Some reflections on this issue are voiced in this contribution.