In order to investigate symptoms prevalence related to visual display terminal (VDT) syndrome, and to evaluate the variables affecting the development of the VDT syndrome, a questionnaire survey was conducted on 119 (92 men and 27 women) VDT operators who had been engaged in one plant design company in Seoul. The results were as follows : The average age of questionnaire respondents was 30. The average years of service were 4.3 years, and the working hours per day with VDT for half of them were more than 4 hours with the average being about 4.7 hours. The majority of subjects (71 persons) were working at computer aided design (CAD) or computer programming tasks. Subjective symptoms of VDT syndrome were divided into 4 groups with musculoskeletal, eye, skin, and industrial fatigue according to their major affected organ. 4 high incidence of complaints of eye discomfort was observed. In the 3 subgroups of industrial fatigue symptom, the highest average group score was accounted for by 'dullness and sleepiness', followed by 'difficulty in concentration', 'bodily projection of fatigue' in the order of sequence, suggesting the heavier mental stress of VDT work rather than physical burden. Relationship among these 4 groups of symptoms showed statistically significant correlations one another. This result suggests that VDT syndrome is a multi-organ disease composed of these 4 symptom groups which were commonly caused by the use of VDT. Multiple regression analysis were used to examine the relationship between risk factors and these symptom groups of VDT syndrome. As the result of analysis, the most important risk factor for VDT syndrome was the average daily VDT working hours. The longer was VDT working hours, the higher was symptom prevalence of VDT syndrome. In addition, daily total working hours including VDT working hours and shift of work also affected the health of VDT users. In order to protect workers from VDT syndrome, it is urgently required to implement standard management recommendations including restriction of VDT working hours and allowance of more sufficient resting time for VDT workers.