An experimental design procedure (based on the response surface method, RSM) was used to investigate the effect of pressure and temperature as operating parameters on the supercritical carbon dioxide (SCCO2) extraction of carotenoids from Dunaliella sauna microalgae. Using RSM method, 11 experiments were performed in random order and empirical correlation was developed. Results indicated that the effect of pressure on yield of extraction is much more than temperature. The most appropriate operating condition to obtain the best extraction yield of carotenoids was found at 400 bar and 55 degrees C (115.43 mu g/g dry microalgae). The recovery of carotenoids at optimum condition with supercritical extraction was half (47%) of the solvent extraction yield. The highest carotenoids/chlorophylls ratio (11.09) was obtained at 300 bar and 30 degrees C which show the selectivity of this technology. Under these operating conditions the separation and purification of the two extracted pigments facilitated and a higher selectivity is obtained. (C) 2016 Elsevier B.V. All rights reserved.