Narcotics "body packing" can be detected in abdominal X-rays by the ring shadow caused by air trapped in the packs. In a series of 82 cases admitted for abdominal X-ray in Helsinki, Finland, in 1982 through 1988, we encountered 9 (11.0%) true positives, 3 (3.6%) false positives, and 1 (1.2%) false negative. The false positives were due to the constipation often associated with the narcotics abuse. The false negative X-ray diagnosis was attributable to an inexperienced radiologist. False negatives may also be associated with packets containing marijuana, packs with few wrappings, aluminum-foil coated packs, and machine-packed narcotics. Searching for trapped air in radiographs, repeated X-raying by an experienced radiologist, use of computed tomography, or combined urinary drug screening may be applied to diminish false findings and to avoid unnecessary arrest for the purpose of fecal screening over several days.