Many of epidemiological studies have certified the relationship between welding and various forms of health damages. In our study we performed an immunological research within a group of twenty men, working in the risky environment of manufacturing of stainless steel constructions (11 welders and 9 grinders, average age was 31 years, 55% of smokers, average time period in welding occupational exposure was 8 years). The exposed group of men was compared with a group of healthy blood donors, marked as the control group (people with various types of employment, living in same locality as a people from exposed group). People within the control group were not occupationally exposed to harmful chemical compounds (from 30 to 100 men were chosen for the individual immune parameters, average age of the whole group was 38 years, 40% of smokers). When compared with the control group, the exposed group of welders and grinders showed higher level of C3 complement (p < 0.001), orosomucoid (p < 0.05), beta-2-microglobulin (p < 0.001), neopterin (p < 0.001) and all fagocytic cells (p < 0.001). On the contrary, in the group of exposed people decreased values of IgA (p < 0.001), IgG (p < 0.001), IgM (p < 0.001), transferin (p < 0.001), alpha-1-antitrypsin (p < 0.001), alpha-2-macroglobulin (p < 0.001), haptoglobulin (p < 0.001) and ceruloplasmin (p < 0.05) were found. Some of these changes were characteristic for the exposed group. They could be considered as precursors of biological markers of effect for given type of exposure.