Seventeen persons (2 women and 15 men), who were exposed to glycolethers in a varnish production plant, were examined according to their external and internal solvent exposure. The workers in the production plant (n = 12) were exposed to average concentrations of ethoxyethanol, ethoxyethyl acetate, butoxyethanol, 1-methoxypropanol-2, 2-methoxypropyl-1-acetate and xylene of 2.8; 2.7; 1.1; 7.0; 2.8 and 1.7 ppm. In the air of the store (n = 3) and in the laboratory (n = 2) only minor concentrations of xylene respectively xylene and ethoxyethyl acetate could be measured. Internal exposure was estimated by measuring butoxyethanol (BE) in blood as well as ethoxyacetic acid (EAA) and butoxyacetic acid (BAA) in urine samples. Urine samples were taken pre- and post-shift. As expected, the highest values were found in the varnish production. The average post shift concentrations of BE, EAA and BAA were 121.3 micrograms/l; 167.8 and 10.5 mg/l. The relatively high concentrations of EAA and BAA in pre-shift samples can be explained by the long half-lives of these metabolites. According to our findings most of the glycolethers were taken up through the skin. Comparing our results with those reported in the literature we think that a future tolerable limit value for the concentration of ethoxyacetic acid in urine should be in the order of 100 to 200 mg/l.