Background: 1,2:3,4-Diepoxybutane (DEB) is a substance classified to a group of carcinogens. The maximum admissible concentration (MAC) value for this substance in workplace air is not specified in Poland. Due to the fact that DEB has been used in domestic companies there is a need to develop a sensitive method for determining 1,2:3,4-diepoxybutane in the work environment. Material and Methods: The studies were performed using gas chromatography (GC) technique. An Agilent Technologies chromatograph, series 7890A, with a mass selective detector (5975C, Agilent Technologies, USA) was employed in the experiment. Separation was performed on a capillary column with Rtx-5MS (30 m × 0.25 mm × 0.25 μm) (Restek, USA). Results: The developed method consists in passing the known volume of air through sorbent tube filled with activated carbon, desorpting the DEB vapor with dichloromethane/methanol mixture (95:5, v/v) and analyzing the obtained solution. The method is linear (r = 0.999) within the investigated working range of 0.09–2.06 μg/ml, which is equivalent to air concentrations of 5–114 μg/m³ for a 18 l air sample; limit of detection (LOD) − 9.89 ng/ml and limit of quantification (LOQ) − 29.67 ng/ml. Conclusions: The described analytical method enables selective determination of 1,2:3,4-diepoxybutane in the workplace air in the presence of 1,3-butadiene, 1,2-epoxypropane, toluene, styrene and 1,2-epoxy-3-phenoxypropane. The method is characterized by good precision and accuracy and meets the criteria for measurement of chemical agents, listed in PN-EN 482:2012. Med Pr 2016;67(5):645–652