The DC-DC converters operate extensively in a variety of industrial applications such as electric vehicles, renewable energy systems, aerospace applications, consumer electronics (smartphones, laptops, etc.) and energy storage solutions. The reliability of the DC-DC converters is of a greater significance. The research endeavours made in enhancing the reliability of the DC-DC converters are still very limited and dispersed. Due to the rapid growth in semiconductor technology, the DC-DC converters have an endless number of topologies, with various operating principles and functionalities. Enhancement of the reliability of all types of DC-DC converters is still a challenging task. Power switches are the most fragile components in converter circuits, which inherently fall prey to the faults occurring in the system. Hence, there is always a requirement to take appropriate remedial measures to deal with all kinds of faults. Further, in order to detect the occurrence of fault a fast faultdiagnosis and fault-tolerant strategies in the DC-DC converters is mandatory and the same has to be embedded in the converter for safety purpose. In view of the importance of the same, the fault-diagnostic algorithms and fault-tolerant strategies developed in the literature, by various researchers are furnished in a single document after conducting an exhaustive review. © The Institution of Engineering and Technology 2019.