In this work, sunflower oil (SF) and methyl ester of sunflower oil (ME-SF) were introduced as two green solvents for extracting astaxanthin (ASX) from shrimp processing waste. The effects of temperature (25, 45, 70 degrees C), solvent to waste ratio (3, 6, 9), waste particle size (0.6 and 2.5 mm) and moisture content (0% and 86.8%) as well as stirrer speed (120, 200, 400 rpm) were studied during the process. In all the experiments, ASX yields from extraction with ME-SF were higher than with SF. For both solvents, the highest ASX content using a short extraction time was achieved at a temperature of 70 degrees C, a solvent to waste ratio of 9 and a stirrer speed of 400 rpm while the waste particle size and moisture content were 0.6 mm and 86.8%, respectively. ME-SF and SF seem promising solvents extracting respectively about 80% and 60% of the total ASX extracted by organic solvents. (C) 2015 Elsevier Ltd. All rights reserved.