Abstract: The present invention relates to thienyl substituted acylguanidine derivatives, such as compounds of formula (I) in which R1, R2, R4, R6, A, B and D have the meanings indicated in the claims, their physiologically tolerable salts and their prodrugs. The compounds of the present invention are valuable pharmaceutical active compounds. They are vitronectin receptor antagonists and inhibitors of bone resorption by osteoclasts. They are suitable, for example, for the therapy and prophylaxis of diseases which are caused at least partially by an undesired extent of bone resorption, for example of osteoporosis. The invention furthermore relates to processes for the preparation of thienyl substituted acylguanidines, their use, in particular as active ingredients in pharmaceuticals, and pharmaceutical preparations comprising them.