This paper presents a fuzzy sliding mode controller for synchronization of two 4-D hyperchaotic systems. This paper describes two 4-D hyperchaotic systems a LU system and a Newton-Leipnik system. A LU system is defined as master system and the Newton-Leipnik system is defined as the slave system. In the controller design, an additional controller is designed using a sliding surface to ensure the sliding motion through the entire state trajectory. The method of designing a fuzzy sliding mode ...