We studied 150 metal workers occupationally exposed to metals and metalworking fluids (MWFs) to determine the prevalence and nature of contact dermatitis. 150 office workers were used as non-exposed control group. Questionnaires were administered to evaluate occupational and non-occupational exposure. All subjects underwent a dermatological examination and patch-testing with standard allergen series and MWFs used in the plant. Twenty-eight metal workers (18.6 %) presented minor skin disorders involving the hands (vs. only 2% of the controls), ten (6.6%) had major disorders (similar to the figure for the control group -5.4%), and 112 (74.8%) had no lesions, as opposed to 92.6% of the control group. Positive patch tests were found in ten metal workers: eight had major skin disorders (six to nickel, cobalt and chromium, one to nickel and cobalt, one to nickel) and the remaining two were asymptomatic (one positive for nickel and chromium, one for nickel). Among the controls there were three cases of positivity, all among asymptomatic subjects. Patch tests with MWFs were negative. The prevalence of dermatoses among the metal workers was significantly higher than that of controls (p < 0.01), and all cases of allergy in this group were provoked by metals themselves. In spite of the high level of automation currently used in the metal industry, the prevalence of occupational diseases among metal workers remains high. The most common disorders are those involving the skin, in most cases dermatitis provoked by contact with metalworking fluids (MWFs) and metals themselves. MWFs are oils or oil-based emulsions used for lubricating and cooling the cutting edge of tools, elimination of metal chips and refinishing the surface of the final product. The neat, or insoluble, oils used during the first part of this century, have been almost completely replaced by oil-in-water emulsions (l). The composition of these fluids is complex, and they often contain a number of additives (e.g., emulsifiers, preservatives, corrosion inhibitors, biocides, antifoaming agents, hard-water stabilizers, dyes, fragrances) (2). They may also contain contaminant metals such as nickel (3), chrome (4) or cobalt (5) that leak into the oil during use. All of the above substances can be irritants and / or sensitizers (6, 7), provoking various types of cutaneous symptoms mainly on the hands and arms.A few attempts have been made to determine the actual prevalence of dermatoses among metal workers (6,8) 0394-6320 (2000)