Communication of information concerning the sender's quality or intentions is essential for maintaining territories. Receivers that respond to dishonest signals that provide misleading information about quality or intent should therefore be selected against. Honest signals prevent cheating because they are constrained by factors such as the energetic costs of the signal. We tested the hypothesis that “All Trunk Raised” (ATR), a behavior that occurs in territorial contests in terrestrial salamanders, is an honest indicator of aggressive intent. In staged contests between pairs of Ozark Zigzag Salamanders (Plethodon angusticlavius), individuals that performed bites spent more time exhibiting ATR prior to biting than individuals that did not bite. In addition, we examined whether ATR is an energetically costly behavior. In metabolic trials, individuals that performed more ATR produced more CO₂. These results support the hypothesis that ATR is an honest indicator of aggressive intent in this species.