Two opposed parties seek to infl‡uence an uninformed decision maker. They invest in acquiring information and select what to disclose. The decision maker then adjudicates. We compare this benchmark with a procedure allowing adversarial cross-examination. A cross-examiner tests the opponent in order to persuade the decision maker that the opponent is deceitful. How does the opportunity or threat of cross-examination affect the parties' ’behavior? How does it affect the quality of decision-making? We show that decision-making deteriorates because parties are less likely to acquire information and because cross-examination too often makes the truth appear as falsehood. Next, we consider a form of controlled cross-examination by permitting the cross-examined to be re-examined by his own advocate, i.e., counter-persuasion. More information then reaches the decision maker. Decision-making may or may not improve compared to the benchmark depending on how examination is able to trade off type 1 and 2 errors.