High-pressure injection injuries of paint, sand, lubricating fluid and other materials are uncommon, but important because they are also on the list of injuries missed in the accident ward. Typically, the patient has briefly placed their hand or fingertip over a pressure spray nozzle, sustaining an injection of material into the soft tissues. Under pressure, this material tracks up tissue planes next to flexor tendons, nerves, arteries and through the named bursae and compartments of the hand and arm. Debris may be driven from the fingertip to the chest wall. The examiner may be misled by a small visible wound and (depending on the material injected) relatively few physical findings, and the patient may be discharged only to return within 24 hours because of worsening symptoms. X-rays may show soft tissue air, particulate debris, or pigment in certain types of paint. Treatment is emergency radical debridement. The pressure-injected m aterial tends to track through the loose areolar tissue along longitudinal structures, and careful debridement may allow preservation of all vital structures. In contrast, late surgical treatment may require en bloc tumor-like excision of contaminated zones.