The 17beta-cyano-18a-homo-19-nor-androst-4-ene derivatives of the present invention possess gestagenic activity. They have the general chemical formula 1, in which Z is selected from the group comprising O, two hydrogen atoms, NOR and NNHSO2R, in which R is hydrogen or C1-C4-alkyl, R4 is hydrogen or halogen, furthermore either: R6a, R6b together form methylene or 1,2-ethanediyl or R6a is hydrogen and R6b is selected from the group comprising hydrogen, methyl and hydroxymethylene, and R7 is selected from the group comprising hydrogen, C1-C4-alkyl, C2-C3-alkenyl and cyclopropyl, or: R6a is hydrogen and R6b and R7 either together form methylene or are omitted with formation of a double bond between C6 and C7, R9, R10 are hydrogen or are omitted with formation of a double bond between C9 and C10, R15, R16 are hydrogen or together form methylene, R17 is selected from the group comprising hydrogen, C1-C4-alkyl and allyl, at least one of the substituents R4, R6a, R6b, R7, R15, R16 and R17 not being hydrogen or R6b and R7 being omitted with formation of a double bond between C6 and C7 or being omitted with formation of a double bond between C1 and C2, and moreover comprise their solvates, hydrates, stereoisomers, diastereomers, enantiomers and salts.
