ObjectiveTo validate the use of ultrasound technology for the positioning and leveling of intercostal needle placement. DesignDouble-blinded experimental study. SettingAn anatomy laboratory. ParticipantsTwo board-certified physical medicine and rehabilitation physicians, 2 first-year medical students, 1 anatomist, and 8 cadavers. InterventionsFour unfixed cadavers were used for unguided needle placement, and 3 unfixed and 1 partially fixed cadavers were used for ultrasound-guided needle placement. Ultrasound-guided needle placement was then confirmed with computed tomography and blind dissection. Main Outcome MeasureThe accuracy of needle placement. ResultsThe unguided study showed needle placement in an intercostal muscle 89% of the time, but in only 15.4% of the time was the correct level sampled. In the 96 needle placements completed, the unguided needle placements had an accuracy of 8.3%, while ultrasound-guided needle placements had an accuracy of 93% (χ2 with P<.005). ConclusionsUltrasound guidance dramatically increases needle placement accuracy for intercostal nerve blocks and intercostal muscle sampling for electromyography.