We investigated the 1,004 workers who worked in a automobile factory to study the epidemiologic characterist of dermatoses due to cutting oils. Among the workers, 667(66.4%) answered the questionnaire. They are belong to 5 departments of the factory-the Engine-Work(86), Power train Assembly(17). We measured the oil mist concentration in air of the departments and examined the workers who had dermatologic symptoms. The results were follows; 1) Oil mist concentration; Of all measured points(52), 9 points(17.2%) exceeded 5mg/m3-the time-weighed PEL- and one department had a upper confidence limit(95%) higher than 5mg/m3. 2) Dermatologists examined 213 workers. 172 of them complained any skin symptoms at that time-itching(32.5%), papule(21.6%), scale(15.7%), vesicle(12.5%) in order. The abnormal skin site found by dermatologist were palm(29.3%), finger & nail(24.6%), forearm(16.2%), back of hand(8.4%) in order. 3) As the result of physical examination, we found that 160 workers had skin diseases. Contact dermatitis was the most common; 69 workers had contact dermatitis alone(43.1%), 11 had contact dermatitis with acne(6.9%), 10 had contact dermatitis with folliculitis(6.3%), 1 had contact dermatitis with acne & folliculitis, and 1 had contact dermatitis with abnormal pigmentation. Others were folliculitis(9 workers, 5.6%), acne(8, 5.0%), folliculitis & acne(2, 1.2%), keratosis(1, 0.6%), abnormal pigmentation(1, 0.6%), and non-specific hand eczema(47, 29.3%). 4) The prevalence of any skin diseases was 34.0 per 100 in cutting oil users, and 13.3 per 100 in non-users. Especially, the prevalence of contact dermatitis was 23.0 per 100 in cutting oil users and 4.3 per 100 in non-users. 5) We tried patch test(standard series, oil series, organic solvents) on 49 patients to differentiate allergic contact dermatitis from irritant contact dermatitis and found 20 were positive. 6) In a multivariate analysis(independent=age, tenure, kinds of cutting oil), the risk of skin diseases was higher in the water-based cutting oil user and both oil user than non-user or neat oil user(odds ratio were 2.16 and 2.78, respectively). And the risk of contact dermatitis was much higher at the same groups(odds ratio were 5.16 and 6.82, respectively).