The object of this study is supercritical carbon dioxide extraction of flax seed oil (Linum usitatissimum L.) at the pressures of 30, 40 and 50 MPa, temperatures of 47 and 52 deg C, extraction time of 4 h, special flows of solvent of 8.8 kg/(kg h), and particle size fractions of grinding material of 0.16–0.315, 0.315–0.80 and 0.80–2.00 mm. Supercritical fluid extraction (SFE) of the flax seed oil on the laboratory scale, with the special interest in the influence of the extraction pressure, temperature, extraction time, and grinding of ground material on the overall yield of the flax seed oil was investigated. Experimental results of the oil yields were compared with the data obtained by the mathematical model of Hong et al. I.K. Hong, S.W. Rho, K.S. Lee, K.P. Yoo, Korean J. Chem. Eng. 7 (1990) 40, presented in the literature.