The design and synthesis of molecular switches is of growing importance considering the steep increase in the production of consumer electronics in the recent years. The function of these devices is based on binary electronic circuits and can be achieved by use of bistable magnetic materials. This article reviews four types of molecular systems, which can be switched between two spin states in response to an external stimulus, illustrating working principles that can motivate the design of systems for practical applications. As an outlook, organic diradicaloid molecules are introduced as potential molecular magnetic switches that do not rely on the use of metals.