tation of complex nonlinear control algorithms. A persistent bottleneck, however, remains the manner in which suitable control strategies can be derived in both approaches. Each method requires optimisation of several parameters, which is usually not a trivial problem for many optimisation techniques. This paper will discuss two important issues related to rule-based fuzzy and neural systems. These issues are knowledge representation and knowledge acquisition. Knowledge representation refers to the manner in which knowledge can be expressed in connectionist, neural systems in order to preserve the advantages of fuzzy-based systems. Knowledge acquisition, on the other hand, is the manner in which the rules that represent fuzzy knowledge are obtained and stored, taking advantage of neural learning techniques. The primary objective of using fuzzy-neural approaches is to develop systems that are capable of automatic acquisition of knowledge for given network representations. In that regard, the paper will also discuss the implementation of learning using evolutionary algorithms in neuralnetwork-based fuzzy systems. Typical applications for such systems include the control of unknown nonlinear plants, a case study of which will be presented.Neural networks are widely used for system modelling and control because of their ability to approximate complex nonlinear functions [1]. Fuzzy systems, similarly, have been shown to be able to approximate or model any nonlinear system. Wang and Mendel [2], for example, showed that combinations of fuzzy membership functions are capable of approximating any continuous function to any given level of accuracy. Fuzzy-logic and neural systems, however, have very contrasting application requirements. Fuzzy systems are appropriate if sufficient expert knowledge about the process is avail-