Medical records were selected from the Danish National Patient Register in order to study individuals between the ages of 17 and 49 years in the general population who, during an 8-year period, were admitted at least 10 times to a general hospital (N = 282). Fifty-six subjects (19%) were found to be persistent somatizers, i.e. they were admitted repeatedly to general hospitals for physical symptoms without an organic basis. This corresponded to a frequency of persistent somatization in the population 0.6 per 1000 men and 3.2 per 1000 women. Seventy-five per cent of the subjects were under 25 years old at the onset of their disorder, and all were under 35. Their illnesses were long-lasting, with one-third having a hospital 'career' of more than 20 years. They had a lifetime median of 22 medical admissions, and had utilized 3% of the general population's admissions to non-psychiatric departments. This investigation shows that persistent somatization is not a rare phenomenon, and that taking the heavy utilization of health-care resources into account it constitutes a considerable problem for the health-care system. The long hospital career and the relatively early start of somatization in some subjects emphasize the importance of an early identification of the condition, and of efforts to try to prevent its persistence.