The second international workshop on big data, cloud, and IoT technologies for smart cities is a forum for researchers in academia and industry who are interested in big data, cloud, and IoT technologies for smart cities and their use cases. The goal of this workshop is to share novel ideas, research progress, and smart city use cases, and to discuss future directions of smart city technologies. The workshop focuses on the added value interconnection among state-of-the-art technologies such as, Big Data, cloud/edge computing, Internet of Things, blockchains, cybersecurity and others having as aim to provide services in the context of the smart cities.