A liquid crystal medium having negative dielectric anisotropy comprising one or more compounds of formula I in which R L denotes H, a straight chain or branched alkyl or alkoxy radical having 1 to 15 C atoms, where one or more CH 2 groups in these radicals may each be replaced, independently of one another, by -C≡C-, -CF 2 O-, -OCF 2 -, -CH=CH-, -O-, -CO-O- or -O-CO- in such a way that O atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by halogen, X L denotes F, Cl, CN, CHF 2, CF 3, or OCF 3, Y L denotes H, F, Cl or CH 3, and one or more compounds selected from the group of compounds of the formulae IIA, IIB, IIC and IID, in which R 2A, R 2B, R 2C and R 2D each, independently of one another, denote H, an alkyl or alkenyl radical having up to 15 C atoms which is unsubstituted, monosubstituted by CN or CF 3 or at least monosubstituted by halogen, where, in addition, one or more CH 2 groups in these radicals may be replaced by -O-, -S-, -C≡C-, -CF 2 O-, -OCF 2 -, -OC-O- or -O-CO- in such a way that O atoms are not linked directly to one another, L 1 to L 4 each, independently of one another, denote F, CI, CF 3 or CHF 2, Y denotes H, F, Cl, CF 3, CHF 2 or CH 3, Z 2, Z 2B and Z 2D each, independently of one another, denote a single bond, -CH 2 CH 2 -, -CH=CH-, -CF 2 O-, -OCF 2 -, -CHzO-, -OCH 2 -, -COO-, -OCO-, -C 2 F 4 -, -CF=CF- or -CH=CHCH 2 O-, p denotes 0, 1 or 2, q denotes 0 or 1, and v denotes 1, 2, 3, 4, 5, or 6, wherein the mixtures X-1 and X-2 having the following compositions Mixture X-1: CC-3-V1 8.0 % CC-4-V1 20.0 % CCH-301 10.5 % CCH-303 2.0 % CC-3-4 0.5 % CCY-3-O2 11.0 % COB -2-O4 7.5 % CLP-3-T 1.0% CPY-3-O2 10.5 % CY-3-O2 15.5 % CY-3-O4 3.5 % PP-1-2V1 10.0 % Σ 100.0 % Mixture X-2 B -2O-O4 2.0 % B -2O-O5 4.0 % CC-3-V 37.0 % CC-3-V1 3.0 % CCP-V-1 14.5 % CCY-3-O2 11.5 % CCY-5-O2 3.0 % COB -2-O4 10.0 % CY-3-O2 14.0 % CLP-3-T 1.0 % Σ 100.0 % are excluded. R L denotes H, a straight chain or branched alkyl or alkoxy radical having 1 to 15 C atoms, where one or more CH 2 groups in these radicals may each be replaced, independently of one another, by -C≡C-, -CF 2 O-, -OCF 2 -, -CH=CH-, -O-, -CO-O- or -O-CO- in such a way that O atoms are not linked directly to one another, and in which, in addition, one or more H atoms may be replaced by halogen, X L denotes F, Cl, CN, CHF 2, CF 3, or OCF 3, Y L denotes H, F, Cl or CH 3, R 2A, R 2B, R 2C and R 2D each, independently of one another, denote H, an alkyl or alkenyl radical having up to 15 C atoms which is unsubstituted, monosubstituted by CN or CF 3 or at least monosubstituted by halogen, where, in addition, one or more CH 2 groups in these radicals may be replaced by -O-, -S-, -C≡C-, -CF 2 O-, -OCF 2 -, -OC-O- or -O-CO- in such a way that O atoms are not linked directly to one another, L 1 to L 4 each, independently of one another, denote F, CI, CF 3 or CHF 2, Y denotes H, F, Cl, CF 3, CHF 2 or CH 3, Z 2, Z 2B and Z 2D each, independently of one another, denote a single bond, -CH 2 CH 2 -, -CH=CH-, -CF 2 O-, -OCF 2 -, -CHzO-, -OCH 2 -, -COO-, -OCO-, -C 2 F 4 -, -CF=CF- or -CH=CHCH 2 O-, p denotes 0, 1 or 2, q denotes 0 or 1, and v denotes 1, 2, 3, 4, 5, or 6, Mixture X-1: CC-3-V1 8.0 % CC-4-V1 20.0 % CCH-301 10.5 % CCH-303 2.0 % CC-3-4 0.5 % CCY-3-O2 11.0 % COB -2-O4 7.5 % CLP-3-T 1.0% CPY-3-O2 10.5 % CY-3-O2 15.5 % CY-3-O4 3.5 % PP-1-2V1 10.0 % Σ 100.0 % Mixture X-2 B -2O-O4 2.0 % B -2O-O5 4.0 % CC-3-V 37.0 % CC-3-V1 3.0 % CCP-V-1 14.5 % CCY-3-O2 11.5 % CCY-5-O2 3.0 % COB -2-O4 10.0 % CY-3-O2 14.0 % CLP-3-T 1.0 % Σ 100.0 % are excluded.