Fuzzy logic has recently been widely used to model in many areas of civil engineering applications. Especially as a result of the findings of experimental studies with fuzzy logic to predict good results have been obtained. In this study, Portland cement is composed of fly ash and silica fume with determined proportional. By this procedure, eight different mixtures were prepared and the effect of cement was investigated on the starting and finishing time of the setting. According to the results obtained in the setting time and finishing, all the mixing ratio of the prolonged period of time was determined. Also, by using fuzzy logic method, prediction model was formed based on the quantity of fly ash and silica fume to predict the initial and final setting times of cement, which could not be determined with experimental approaches. The experimental results are compared with the fuzzy logic results, and the correlation coefficients for the initial and final setting time are found 0.96 and 0.92, respectively. These results show that the developed model can be successfully applied in the cement industry.