RATIONALE AND OBJECTIVE: Pneumothorax (Ptx) is a life-threatening complication that can result from trauma, mechanical ventilation, and invasive procedures. Infrared thermography (IRT), a compact and portable technology, has become highly sensitive. We hypothesized that IRT could detect Ptx by identifying associated changes in skin temperature. MATERIALS AND METHODS: Bilateral nonpenetrating chest incisions or needle punctures were performed in 21 anesthetized rats. Rats were then randomized to no, bilateral, left, or right Ptx by either open (n = 16) or closed percutaneous (n = 5) puncture through selected pleurae. Real-time thermographic images and surface temperature data were acquired with a noncooled infrared camera. RESULTS: In all cases, blinded observers correctly identified each Ptx with real-time grayscale image analysis. When compared to either the ipsilateral baseline or an abdominal reference, experimental Ptx produced a significantly greater decrease in surface temperature when compared to non-Ptx control. CONCLUSIONS: These results demonstrate that portable infrared imaging can rapidly and accurately detect changes in thoracic surface temperature associated with experimental pneumothorax.