Tomato seed oil was extracted with supercritical carbon dioxide in a semibatch-flow extraction apparatus. The effect of milling of seeds and solvent flow rate on the extraction behavior was studied. The extraction rate increased as solvent flow rate increased. Milling the seeds,prior to extraction enhanced the extraction rate. During extraction from milled seeds, the solute from the cells opened by milling was extracted fast, and the solute inside the cell walls was extracted slowly. Mathematical models based on two distinct extraction periods with different extraction rate were applied to analyze the experimental data. The models simulated the extraction behavior satisfactorily.