The authors report a case of an 18-year-old man with T-cell acute lymphocytic leukemia who developed hemorrhagic pancreatitis after chemotherapy. He subsequently developed abdominal compartment syndrome (ACS). Computed tomography showed a large fluid-filled mass in the area of the pancreas. As a result of the instability of his condition, surgical decompression, the standard therapy for ACS, was believed to carry significant morbidity and potential mortality. The patient underwent ultrasound-guided drainage of the peripancreatic fluid, which decreased his abdominal pressures and improved his clinical status. Without this procedure, the patient may not have tolerated subsequent surgery.