Psychologic factors were studied in 10 patients with symptoms presumed to be caused by electricity (EG) and in 10 patients with symptoms presumed to be caused by visual display units (VG) and compared with a sex- and age-matched control group (CG). Psychologic differences between the EG and VG were also measured. The symptoms presumed to be caused by electricity or visual display units were registered, and the personality, psychologic functioning, and quality of life were determined by using the Karohnska Scales of Personality (KSP), an additional Personality Scale (PS), a Psychological Functioning Scale (PFS), and a Quality of Life Scale (QLS). The results showed that the commonest general symptoms in the EG/VG were skin complaints, fatigue, pain, and dizziness, and the commonest oral symptoms were gustatory disturbance, burning mouth, and temporomandibular joint dysfunction. The patients in the EG described more different types of both general and oral symptoms than those in the VG. The result showed that the VG scored significantly higher only in the KSP Somatic Anxiety and Muscular Tension scales, and the EG scored significantly lower in the KSP Socialization scale and significantly higher in the Somatic Anxiety, Muscular Tension, and Psychasthenia scales. In addition, only the EG differed significantly on the PS, PFS, and QLS. The EG differed significantly in such psychologic aspects as being more fatigued in the PS, in having more difficulty in concentrating, in taking the initiative, and in getting on with people in the PFS and experiencing inactivity and visiting other people rarely in the QLS. The conclusion was that patients with symptoms presumed to be caused by electricity and visual display units differed from each other psychologically and, therefore, should be handled clinically in different ways. The need for an interdisciplinary approach to these patients is emphasized.