Plasma‐based ion implantation and deposition (PBII&D) technology has been developed rapidly in the past decade. This technique is especially promising for modifying three‐dimensional components. In PBII&D, plasma is generated in the entire processing chamber and then surrounds the components. When a train of negative voltage pulses are applied to the parts, ions are drawn to all the surfaces exposed to the plasma. At a high energy, ions are implanted to the surfaces, but at a low energy and with a proper precursor gases, ions are deposited to form a film. This technology has found applications in many areas including semiconductors, automotive, aerospace, energy and biomedical. This article reviews PBII&D fundamentals, describes features of various PBII&D systems and plasma sources, and discusses implantation and deposition techniques. The paper will also present application examples of this technology. © 2004 American Institute of Physics