Liquid crystal medium, characterised in that it comprises one, two or more compounds of formula C in which R C denotes H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 12 C atoms, or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 12 C atoms, in which one or more CH 2 -groups may be replaced by L C1, L C2 identically or differently, denote H, Cl or F, R C1, R C2, R C3, R C4, R C5 and R C6 identically or differently, denote H, F, Cl, or alkyl having 1 to 6 C atoms, or cyclopropyl, cyclobutyl or cyclopentyl; and one or more dielectrically positive compounds selected from the group of compounds of the formulae I, II and III, in which R 1 denotes H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms, or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, in which one or more CH 2 -groups may be replaced by n is 0, 1 or 2, on each occurrence, independently of one another, denote or, in which R L, on each occurrence identically or differently, denotes H or alkyl having 1 to 6 C atoms, and wherein alternatively denotes or R 2 denotes H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms, or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, in which one or more CH 2 -groups may be replaced by Z 21 denotes trans-CH=CH-, trans-CF=CF- or -C≡C-, and and independently of one another, denote in which R L, on each occurrence identically or differently, denotes H or alkyl having 1 to 6 C atoms; R 3 denotes H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms, or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, in which one or more CH 2 -groups may be replaced by one of Z 31 and Z 32, denotes trans-CH=CH-, trans-CF=CF- or -C≡C- and the other one, independently thereof, denotes-C≡C-, trans -CH=CH-, trans-CF=CF- or a single bond, and to independently of one another, denote in which R L, on each occurrence identically or differently, denotes H or alkyl having 1 to 6 C atoms, and wherein alternatively denotes where the medium comprises one or more compounds of formula III, and further characterised in that the medium comprises one or more compounds of the formula T in which R T denotes halogen, CN, NCS, R F, R F -O- or R F -S-, wherein R F denotes fluorinated alkyl or fluorinated alkenyl having up to 12 C atoms, and on each occurrence, independently of one another, denote L 1 and L 2 identically or differently, denote Cl, F, alkyl having 1 to 6 C atoms or cyclopropyl, cyclobutyl or cyclopentyl, and t is 0, 1 or 2. R C denotes H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 12 C atoms, or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 12 C atoms, in which one or more CH 2 -groups may be replaced by L C1, L C2 identically or differently, denote H, Cl or F, R C1, R C2, R C3, R C4, R C5 and R C6 identically or differently, denote H, F, Cl, or alkyl having 1 to 6 C atoms, or cyclopropyl, cyclobutyl or cyclopentyl; and R 1 denotes H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms, or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, in which one or more CH 2 -groups may be replaced by n is 0, 1 or 2, on each occurrence, independently of one another, denote or, in which R L, on each occurrence identically or differently, denotes H or alkyl having 1 to 6 C atoms, and wherein alternatively denotes or R 2 denotes H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms, or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, in which one or more CH 2 -groups may be replaced by Z 21 denotes trans-CH=CH-, trans-CF=CF- or -C≡C-, and and independently of one another, denote in which R L, on each occurrence identically or differently, denotes H or alkyl having 1 to 6 C atoms; R 3 denotes H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms, or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, in which one or more CH 2 -groups may be replaced by one of Z 31 and Z 32, denotes trans-CH=CH-, trans-CF=CF- or -C≡C- and the other one, independently thereof, denotes-C≡C-, trans -CH=CH-, trans-CF=CF- or a single bond, and to independently of one another, denote in which R L, on each occurrence identically or differently, denotes H or alkyl having 1 to 6 C atoms, and wherein alternatively denotes where the medium comprises one or more compounds of formula III, and further characterised in that the medium comprises one or more compounds of the formula T in which where the medium comprises one or more compounds of formula III, and further characterised in that the medium comprises one or more compounds of the formula T in which R T denotes halogen, CN, NCS, R F, R F -O- or R F -S-, wherein R F denotes fluorinated alkyl or fluorinated alkenyl having up to 12 C atoms, and on each occurrence, independently of one another, denote L 1 and L 2 identically or differently, denote Cl, F, alkyl having 1 to 6 C atoms or cyclopropyl, cyclobutyl or cyclopentyl, and t is 0, 1 or 2.