A smart city is a complex system that combines various technologies to provide services and address urban challenges. It aims to minimize human involvement in management, operations, and finance. Blockchain technology is a key component of this system, simplifying procedures and reducing costs through asset decentralization. It enhances transparency, security, and eliminates data duplication. However, implementing blockchain technology in smart cities can be challenging due to lack of knowledge about governing organizations' physical structures. The chapter discusses current trends and challenges in implementing blockchain technology in smart cities, highlighting its potential to aid modernizing network technology and infrastructure management systems.