This systematic review investigates the state of the art of smart fasteners and smart washers. The collected documents were systematically classified, focusing on fasteners and washers equipped with embedded sensors capable of detecting flaws, corrosion, cracks, or monitoring features like structural response, applied load, and preload. The review emphasizes sensor technologies rather than devices made from smart materials. A total of 148 documents were found through electronic databases, of which 32 were thoroughly analyzed and categorized into 5 categories depending on the sensing capabilities, actuating capabilities, ability to transmit data, and their combinations. The analysis showed that most devices incorporate piezoelectric materials as sensing or actuation elements, primarily aimed at detecting fastener loosening or monitoring preload and load in fastened joints. Despite progress, several challenges limit industrial adoption, including sensor integration affecting bolt integrity, durability and calibration issues, and high costs. Few studies address scalability or measurement performance, highlighting the need for reliable, low-cost, and industrially scalable solutions.