The purpose of this study was to examine the medical and demographic characteristics of patients who frequently seek emergency care at a pediatric emergency department (ED). Registration information of ED visits during the study period from 11/1/87 to 5/31/92 (4.6 years) was stored in a data base. Patients with 10 or more ED visits during this study period were considered to be "frequent" ED users. Outpatient and inpatient medical records of these patients were manually reviewed. Demographics, chronic conditions, and the acute conditions for each ED visit were coded and analyzed. During the study period, there were 79,049 ED patient visits under 21 years of age. Of the patients born after 1970, there were 47,451 visits by patients seen one or two times, 25,883 visits by patients seen three to nine times, and 5178 visits by 357 patients seen in the ED ten times or more. Ninety-nine patients were seen more than 15 times, 39 patients were seen more than 20 times, 17 patients were seen more than 25 times, and 10 patients were seen more than 30 times. Two hundred sixty-five of the 357 frequent ED users (74%) had chronic disease conditions. Two hundred and twenty-three of them had good functional status, 25 had mild or moderate impairment in carrying out activities of daily living, and 17 had severe impairment of function. The most common chronic medical conditions were recurrent wheezing (226), neurologic conditions (33), gastrointestinal conditions (13), cardiac conditions (12), and endocrine conditions (9). The other 92 were assessed as healthy children. Patients' immunization status were up to date as of the last ED visit during the study period in 329 patients (92%). Pediatricians were the primary care providers in 339 patients (95%). Medical insurance status of patients follows: private insurance (38%), military (0.3%), Medicaid or state assistance (60%), and no insurance (1.4%). Polynesian ethnic groups were over-represented in the cohort of frequent ED users. We conclude that cultural differences appeared to be an important factor associated with frequent ED use by healthy persons. Medical care resources as measured by immunizations, insurance, and identification of a primary care physician did not appear to be deficient in this cohort of frequent ED users. Since recurrent wheezing is a dominant chronic condition among frequent ED users, pediatric emergency medicine training programs may consider the inclusion of the chronic management of wheezing in their curriculum.