This work aims to study supercritical anti-solvent (SAS) micronization of lutein derived from marigold flowers. Lutein solution in dichloromethane (DCM) or ethanol was atomized into the stream of supercritical carbon dioxide (SC-CO2) through a concentric nozzle in a pressurized vessel. The effects of pressure and SC-CO2 flow rate on morphology, mean particle size (MPS) and particle size distribution (PSD) were investigated. The reduction in lutein MPS from 202.3 mu m of unprocessed lutein to 1.58 mu m and 902 nm could be achieved by SAS micronization using DCM and ethanol, respectively. In both solvent systems, no significant effects of pressure and SC-CO2 flow rate on particle morphology were observed. However, pressure was found to have a significant effect on MPS and PSDs of lutein particles. (C) 2013 Elsevier B.V. All rights reserved.