It’s about 4:30 p.m. on a Friday afternoon in the middle of your trial when an opposing counsel informs you that he has just “found” a witness in your case that he intends to call to testify against you. Of course, this is the first time that you have ever heard of this witness despite having asked for all witnesses names in interrogatory questions, and despite having diligently and properly requested names of all witnesses in each and every deposition you have taken. After your blood pressure returns to a semi-normal level and you compose yourself, you realize that the right thing to do is to object. You rise from your chair, clear your throat and say “objection.” Opposing counsel’s acts amount to “trial by ambush.” Having said this, you hope that the trial court agrees and grants your motion to strike the witness. But then you think to yourself, what if the trial court wants to hear argument in the case, what do I do? What is the law on this matter? Let us start by reviewing the standard trial order entered by most trial judges in the Eleventh Judicial Circuit, in and for Dade County, Florida. The order setting trial normally states that forty-five (45) days before trial: “Parties shall furnish opposing counsel with a written list containing the names and addresses of all witnesses, (impeachment, rebuttal or otherwise) intended to be called at trial and only those witnesses listed shall be permitted to testify.” Most judges will not allow any witness not previously disclosed or ever mentioned, to even get near the courtroom. Nevertheless, there are certain circumstances when a trial judge may be convinced that a witness should be allowed to testify even though they have not been listed prior to the trial. A trial judge may properly allow such witness to testify during the trial if the party presenting the previously undisclosed witness diligently attempted to find said witness and was unsuccessful due to the witness’ unavailability and if the attorney can show that the opposing side is not prejudiced, that the trial will not be disrupted and the orderly and efficient trial of the case may continue. Binger v. King Pest Control, 401 So.2d 1310 (Fla. 1981). In Binger, the Supreme Court of Florida held that a trial court may exclude the testimony of a witness whose name has not been disclosed in accordance with the trial court’s pre-trial order requiring disclosure of all witnesses when the opposing party is prejudiced, the opposing party does not have independent knowledge of the existence of the undisclosed witness, testimony by the undisclosed witness may disrupt the orderly and efficient trial of the case, and no diligence has been shown in attempting to find the witness prior to the actual trial of the case. Binger, 401 So.2d at 1314. Prejudice should be demonstrated before the trial court exercises its discretion to exclude the testimony of a witness whose name has not been disclosed in accordance with a pre-trial order. Binger, 401 So.2d at 1313; Hilton, Vincent, Pipkin, et al. v. Robert T. Hamer, et al., 501 So.2d 1365 (Fla. 4th DCA 1987); William Sayad v. James Alley, 508 So.2d 485 (Fla. 3d DCA 1987). (All cases upheld the trial court’s refusal to allow undisclosed witnesses to testify.) It no longer matters that the undisclosed witnesses are being used simply for impeachment or rebuttal purposes at trial. After the Binger decision, the Florida Supreme Court specifically required that “all witnesses names should be exchanged before trial including rebuttal and impeachment witnesses when the pre-trial order so requires.” 401 So.2d at 1314. Nevertheless, the trial court is afforded broad discretion in deciding whether an undisclosed witness should be allowed to testify. William Sayad v. James Alley, 508 So.2d 485 (Fla. 3d DCA 1987); Binger, 401 So.2d at 1313. The trial court will not be reversed unless the judge abused its discretion. The determination as to whether to allow an undisclosed witness to testify during trial largely will be decided if the party opposing the undisclosed witness can show that it will be prejudiced. Binger 401 So.2d at 1314. Green v. Shoop, 249 So.2d 85 (Fla. 3d DCA 1970); See also, Fuller v. Rinebolt, 382 So.2d 1239 (Fla. 4th DCA 1980). If you apply the above guidelines and rules to your case, you will have no problem in making the right argument that the court should not allow opposing side to try its case by ambush. Chances are you will succeed in preventing the undisclosed witness from testifying in any capacity unless it can be shown that the prejudice can be cured and the undisclosed witness will not substantially endanger the fairness of the proceeding, or disrupt the orderly and efficient trial of the case. Binger, 401 So.2d at 1314. If you are successful in preventing the undisclosed witness from testifying at trial, you should also move in limine to prohibit any testimony, evidence or other mention of the undisclosed witness during the trial by the opposing counsel. This alone may taint the jury’s perception of your case. When confronted with an opposing counsel’s surprise tactic during trial, remember to properly establish your client’s prejudice if the surprise tactic is allowed to proceed during trial. Next, convince the court that the prejudice can not be cured and the matter will affect the fairness of the trial, as well as the orderly and efficient process of the case.