The aim of this work was to study the formation process of dielectrophoretic (DEP) carbon nanotube fibers (CNT-fibers) and characterize the fiber properties relevant to their technological applications. The fiber diameter was shown to increase when applied voltage was increased (up to 350 V(pp)) and when retraction speed was decreased (down from 400 µm s(-1)) in accordance with theoretical expectations. This paper represents the first demonstration of the formation of thick DEP CNT-fibers (up to ∼ ∅0.4 mm). This is an intriguing result, as it expands the diversity of possible applications of the fibers and facilitates their characterization by analytical methods that require large quantities of the material. The performance of these thick fibers was as follows: a density of ∼ 0.35 g cm(-3), a tensile strength of ∼ 15 MPa, a Young's modulus of ∼ 1 GPa, and an electrical resistivity of ∼ 70 mΩ cm.