Act 3 begins outside on a hot day with Mercutio and Benvolio hanging out again. Tybalt shows up looking for Romeo, and Mercutio acts casually. He knows Tybalt is there looking for a fight, so he tries to instigate one. Tybalt takes the bait, and Benvolio worries that they will be caught and put to death because the Prince has decreed that fighting is a capital offense. At that point Romeo shows up, so Tybalt turns his attention toward him. Romeo, having just married Tybalt's cousin, has no interest in fighting him. Romeo tries to tell Tybalt that he loves him and wants them to be friends, but Tybalt won't have it. Mercutio is appalled by Romeo's behavior and thinks he's gone crazy, so Mercutio steps up and fights Tybalt on Romeo's behalf. Romeo steps between them trying to break up the fight, and when Tybalt stabs at Romeo, the sword goes under Romeo's arm and hits Mercutio in the stomach instead. Mercutio, knowing he is badly hurt, curses both families for their feud. Mercutio tries to remain stoic, but he knows that he will die. Benvolio helps to drag him away. Romeo chastises himself for being weak, and when Benvolio returns with the news of Mercutio's death, Romeo becomes angry. He goes after Tybalt saying, "Either thou or I, or both must go with him," meaning that one or both of them are about to die. Romeo then kills Tybalt. Benvolio urges Romeo to flee, knowing that if the Prince finds him, he will be put to death. Romeo leaves.

     A crowd quickly gathers, including the Prince, who wants to know who started the fight. Benvolio blames Tybalt and explains how he killed Mercutio, so then Romeo killed Tybalt. Lady Capulet arrives and demands justice for Tybalt's death. Since Romeo killed Tybalt, Romeo should also die. The Prince points out that Tybalt killed Mercutio, so he deserved to die too. Lord Montague agrees that Romeo doesn't need to die as the two deaths cancel each other out. The Prince doesn't want to hear their arguments. He decides that Romeo's punishment is exile from Verona. If he is found within the town's walls, he will be killed.

     Scene two has Juliet happily awaiting Romeo's arrival that evening for their honeymoon. The Nurse enters with the ladder and the bad news. She tries to tell Juliet what has happened, but she is upset and not being very clear. First, the Nurse says "he's dead," which makes Juliet believe that Romeo is dead. Then, the Nurse clarifies that it is Tybalt who is dead, which is also upsetting since he is Juliet's cousin. Finally, she learns that Romeo is the one who killed him, which is even more upsetting since her new husband has just killed her cousin. She doesn't know how to feel about this news. Lastly, the Nurse reveals that due to his actions, Romeo has been banished from Verona. Juliet, who knew their relationship would be a challenge, has a completely new set of problems. How can she stay married to a husband whom she can never see again? The Nurse sees how distraught Juliet is, so she offers to find Romeo for Juliet, because she thinks she knows where he might be hiding, to tell him that Juliet still loves him and wants to see him before he goes. Juliet gives the Nurse her wedding ring to bring to Romeo as a sign of love and that she wants Romeo to return it back to her finger.