This chapter will focus on the design and synthesis of organic conducting polymers (OCPs) that are capable of effective interaction with biological systems for monitoring and/or stimulation. The choice of appropriate dopants has proven to be critical. It is known that the dopant employed influences surface roughness, surface energy, conductivity and electroactivity. All of these properties will in turn influence the ability to interact with biological systems. On adding to this the introduction of biologically active dopants or covalently attached bioactive entities, we take the control over the performance of these new biocommunication systems to a new level. Here we will focus on implantable systems based on OCPs. We will review the area of implantable biosensors for the monitoring of compounds of therapeutic relevance, as well as the firing patterns from electrically active cellular systems - nerve and muscle. The use of conducting polymer electrodes to stimulate cells to facilitate tissue regeneration is also reviewed. The use of conducting polymers as the basis of electrically controlled delivery systems is also considered. Finally, an emerging area of interest is the use of conducting polymers as the basis for implantable energy systems - biofuel cells and biobatteries.