The effect of sulphur mustard (2,2'-dichlorodiethyl sulphide) exposure through inhalation at 0.5. 1.0 and 2.0 LC50 (21.2, 42.3 and 84.6 mg m(-3) for 1 h) on some urinary variables was studied in female mice at 6, 24 and 48 h and 7 days post-exposure. The urinary excretion and circulatory blood accumulation of uric acid increased significantly. The level of creatine was also elevated significantly as compared to the control at 2 LC50. It is concluded that sulphur mustard alkylates DNA and triggers catabolism of apurinated purine bases in a very short time. The increase in uric acid excretion in urine can be detected only when the exposure concentration is high.