Supercritical carbon dioxide extraction (SFE-CO2) parameters were optimized using response surface methodology and central composite design for lovage (Levisticum officinale Koch.) roots and leaves containing valuable phytoconstituents. Mathematical model predicted the highest yields of extracts from roots and leaves 2.26 and 2.29%, respectively, at 45 MPa pressure, 60 C temperature, 90 min (roots) and 30 min (leaves) extraction time, whereas the yield of hydrodistilled essential oil was 0.24 and 0.74%, respectively. The highest relative content of the most valuable constituent Z-ligustilide in roots and leaves extracts was 77 and 50% at 10 MPa; however, the highest yields of this compound from 100 g of dry material were obtained at the highest applied pressure and constituted 1188 mg (roots) and 540 mg (leaves). This study showed that lovage is a good source of Z-ligustilide and SFE-CO2 is a preferable technique for its isolation.