This invention concerns substituted diaza-spiro-[5.5]-undecane derivatives having neurokinin antagonistic activity, in particular NK.sub.1 antagonistic activity, a combined NK.sub.1/NK.sub.2 antagonistic activity, a combined NK.sub.1/NK.sub.3 antagonistic activity and a combined NK.sub.1/NK.sub.2/NK.sub.3 antagonistic activity, their preparation, compositions comprising them and their use as a medicine, in particular for the treatment and/or prophylaxis of schizophrenia, emesis, anxiety and depression, irritable bowel syndrome (IBS), circadian rhythm disturbances, pre-eclampsia, nociception, pain, in particular visceral and neuropathic pain, pancreatitis, neurogenic inflammation, asthma, COPD and micturition disorders such as urinary incontinence.The compounds according to the invention can be represented by general Formula (I) ##STR00001## and comprises also the pharmaceutically acceptable acid or base addition salts thereof, the stereochemically isomeric forms thereof, the N-oxide form thereof and prodrugs thereof, wherein all substituents are defined as in Claim 1.