The Authors describe the results of a research conducted in order to evaluate the amount of D-glucaric acid in the urine of 131 operating theatre workers exposed to anesthetic gases and in a control group of 25 non-exposed hospital personnel. The comparison of the results of the two groups points out a significant difference (in the exposed members 60.7 +/- 2.4 mumol/1 to 46.7 +/- 4.3 mumol/l [+/- s.e.] in the control group; t-test: p = 0.016). The research also considered the influence of certain variables such as age, sex, smoking, alcohol, drug use and liver disorders. None of these variables has proven to be of significant influence on the D-glucaric acid urinary concentration.