The invention relates to substituted alkylaminopyridazinone derivatives of the general Formula (I), (wherein R₁ is hydrogen or alkyl having 1-4 carbon atoms; one of X and Y stands for hydrogen or halogen and the other represents a group of the general Formula (II), R₂ is hydrogen or alkyl having 1-4 carbon atoms; n is 1, 2 or 3; R₃ stands for hydrogen, alkyl having 1-4 carbon atoms or aryl-(C_1-4 alkyl); Z stands for oxygen; or R₃ and Z together with the groups placed between them form a piperazine ring; and R₄ stands for hydrogen, halogen, trifluoromethyl or alkoxy having 1-4 carbon atoms) and pharmaceutically acceptable acid addition salts thereof. The invention compounds are useful in the treatment of anxiolytic conditions and cognitive disorders.