We reviewed reports from 321 consecutive emergency department (ED) noncontrast, helical "renal stone" abdominal CT scans obtained at a single medical center between April 1996 to June 1997 for incidental findings. Incidental findings were common (45% of scans), and approximately half were rated of "moderate" or "serious" concern by 2 independent reviewers (kappa = 0.72). ED records indicated that only 21% of incidental findings were documented, and only 11 (18%) of cases with findings of "moderate/severe" concern had evidence of follow-up on hospital chart review. Although work-up of these 11 cases did not yield any serious diagnoses, many potentially serious incidental findings without follow-up remain worrisome.