In this paper we present the development of a fuzzy logic based process control system for gari fermentation plant and describe its operation by way of simulation. The model was formulated using the Takagi-Sugeno (TK) fuzzy controller approach. Experiments with models of the system were conducted using MATLAB 6.0 in Windows 2000 XP running on Intel 2Gh environment. The algorithm for the control system is implemented in MATLAB 6.0 using the fuzzy logic toolkit. The results obtained are compared to those for optimum control of the process. For example, we obtain a Mean Square Error (MSE) of 0.643, 0.511, and 0.512 for three experiments conducted for temperature control in the environment. Also, for the pressure variable, we obtained MSE of 0.856, 0.234. and 0.214 respectively for the three separate experiments. These results suggest that, if implemented, this approach can produce fast control response, more effective control, reduced energy consumption and at the same time facilitating the production of better quality fermented and dewatered pulp. (C) 2004 Elsevier Ltd. All rights reserved.