© 2022 Karabuk UniversityNickel-titanium (NiTi) archwires have been widely used in orthodontic treatments at the aligning and leveling step which is the initial stage of the treatment. This review presents the concepts related to NiTi archwires from the materials science and engineering perspective. Analysis of the research profile showed that mechanical properties as a research topic constituted 25.9 % of the research articles published in last two decades. The effects of processing parameters, stress and temperature on phase transformations and corrosion are summarized. The main factors affecting corrosion are stress, temperature and pH of the environment. The effects of surface roughness, brackets and environment on friction are discussed. The surface modification studies are reviewed. The consequences of deflection heat treatment, aging on mechanical properties are described. NiTi archwires are also evaluated in terms of biological properties from a clinical perspective. Clinical studies have focused on mechanical properties and effects on tooth alignment, biofilm formation and Ni ion release. It is anticipated that the studies that will shape the future of the NiTi arcwire field will be on welding of different types of archwires, computational methods, and improvement in coating technologies.