The aim of this study was to map the psychological/psychiatric, odontological and medical aspects of patients with symptoms allegedly related to the side-effects of mercury in dental fillings. A total of 67 consecutive patients and 64 controls matched for age, sex and residential area were included in the study. The most striking result was the high prevalence of psychiatric disorders in the patients (89%) compared to the controls (6%), predominantly somatoform disorders. The personality traits differentiating the patients according to the Karolinska Scales of Personality (KSP) were somatic anxiety, muscular tension, psychasthenia and low socialization. More patients than controls showed alexithymic traits. The prevalence of diagnosed somatic diseases was higher, but not sufficiently so to explain the large difference in perceived health. The multiple symptoms and signs of distress displayed by the patients could not be explained either by the odontological data or by the medical examination. Our data indicate that the patients show sociodemographic and clinical patterns similar to those of somatizing patients. The medicalization of the suffering of these patients and the neglect of psychiatric problems prevent the use of appropriate psychotherapeutic approaches.