The invention relates generally to the field of nucleic acids and more particularly to aptamers that bind to TFPI, which are useful as therapeutics in and diagnostics of bleeding disorders and/or other diseases or disorders in which TFPI has been implicated. In addition, the TFPI aptamers may be used before, during and/or after medical procedures to reduce complications or side effects thereof. The invention further relates to materials and methods for the administration of aptamers that bind to TFPI.