An implantable cochlear implant electrode array (30) that can adopt a first, preferably straight, configuration selected to allow the array to be inserted into the cochlea and at least a second, preferably, spirally curved, configuration wherein the electrode array (30) is adapted to apply tissue stimulation. The electrode array (30) comprises an elongate carrier (31) having a proximal end (37), a distal end (34), and a plurality of electrodes supported by the carrier (31) at respective spaced locations thereon, the carrier (31) is formed, preferably moulded, to preferentially adopt the second configuration or another configuration different to said first configuration. The outer layer (33) is releasably connected to the elongate carrier (31) by an adhesive layer (32) and is formed so as to bias the carrier (31) into the first configuration when connected thereto. A method of forming the electrode array (30) is also disclosed.