Taking its name from an old English case, the rule in Browne v Dunn refers to the principle that if a party wishes to have the evidence of the other party’s witness disregarded or discredited, it must challenge the relevant witness on their evidence in cross examination. The applicability of this rule in international arbitration is controversial, not least because of the tension between, on the one hand, requiring a party to exhaustively cross examine a witness on every contested point of their evidence and, on the other hand, the requirements for procedural economy. International arbitration must also allow for different legal traditions, many of which do not have a similar to practice to those that follow the rule in Browne v. Dunn. This controversy reached a new height in 2019 when, in P v. D, the English High Court refused to enforce an arbitral award, in essence, because there had been a failure to cross examine the witness on a factual point which was pivotal to the tribunal’s deliberation (and therefore, in the Court’s mind, a breach of the rules of natural justice, based on the rule in Browne v. Dunn). This article reviews the applicability of the rule in Browne v. Dunn to international arbitration and makes suggestions for wording that may be included within procedural orders to create clarity and reduce the risk of challenges to the enforceability of an arbitral award.