In an attempt to evaluate working conditions and hazardous environmental factors, a survey on health problems was conducted for 721 employees from 18 industrial plants in Young Dung Po and Sung Dong districts of Seoul in the period from May 1975 to Feb, 1976. The questionnaire and survey was inclusive of all illnesses known as most common to industrial workers (according to the report by Korea Industrial Health Association) of this country and envi ronmental factors pointed out by the workers. The results were as following. 1. The over whelming majority of complaints were psychiatric, ear,eye, and digestive disorders. 2. Those whose work time is the longest have a propotionately higer incidence of complaints especially in eye,ear, neuromusculoskeletal, and neurosensory systems. 3. In females whose occupational history is relatively short, a higher incidence of digestive and skin section disorders was noted and this is especially true among those working in night shift. 4. Among machinery industry workers, most complaints were of eye, ear, and neuro musculoskeletal disturbances, and this fact seems to be closely related to physical over works. 5. Dust and noise were pointed out by the largest number of workers as undisirable conditions in work environment. 6. Distribution of complaints are closely related to the type of industry, and in comparison with the result reported by Korea Industrial Health Association in 1972, the prevalence rates of occupational disorder were similar in our study,