Employers of the companies where carcinogenic chemicals are being processed or used are obliged to ensure safe working conditions for their employees. Butan-2-one oxime, commonly present in alkyd paints or silicone sealants may pose such a risk due to its reclassification as a category 1B carcinogen. Therefore, in Poland new Maximum Admissible Concentrations (MAC) value of 1 mg/m3 was proposed by Interdepartmental Commission for Maximum Admissible Concentrations and Intensities for Agents Harmful to Health in the Working Environment. Assessing exposure to this compound requires a method to be developed for its determination in the workers' breathing zone, which was the aim of the presented study. A method was developed for determining the aerosol concentrations of 2-butanone oxime in the air at workplaces, in the range of 1/10 to 2 of the MAC value, i.e. from 0.1 mg/m3 to 2 mg/m3. The method involves trapping the airborne aerosol of 2-butanone oxime onto a sampler - a glass tube with silica gel, its extraction with methanol and analysis of the resulting solution using gas chromatography with flame ionization detector in the presence of co-substances. Validation parameters were determined according to the guidelines of EN 482. The limit of detection at 6.79 ng/ml and the relative total uncertainty of 11.19% was determined. The method can be used by environmental occupational hygiene laboratories to measure concentrations of butan-2-one oxime in the air.