The oil of Nigella sativa seeds was extracted using hydraulic press. The pressure, temperature and thickness of cake have been optimized, using the Response Surface Methodology to obtain a high oil yield. The physico chemical properties of the seeds and of its oil extracted were also studied. Results showed that the oil Nigella sativa seeds is rich in unsaturated fatty acid s (81.25%) and saturated fatty acid s (18.74%). The unsaturated fatty acid s identified, using gas chromatography, are linoleic acid (54.97%), oleic acid (24.13%) and eicosenoic acid (3.23%). The saturated fatty acid s are palmitic acid (12.50%), behenic acid (2.623%) and arachidic acid (0.338%). The cross section of the seed showed that the oil is localized in the cotyledons and integuments. Statistical analysis revealed that data were adequately fitted in second-order polynomial model. The linear and quadratic terms of temperature, pressure and thickness of cake had significant effects on the oil yield (p<0.05). The optimal conditions to obtain the maximum oil yield (22%) were found to be 120 bars, 60°C and 1.30±0.047 cm for thickness cake.
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