In this study, a fuzzy logic model for predicting compressive strength of concretes containing silica fume (SF) (0, 5, 10%) has been developed using non-destructive testing results [ultrasonic pulse velocity (km/s) and Schmidt hardness (R)]. Experimental results of non-destructive tests and the amount of the SF were used to construct the model. Result have shown that fuzzy logic systems have strong potential for predicting 7, 28, and 90 days compressive strength using ultrasonic pulse velocity (km/s), Schmidt hardness (R), and silica fume content (%) as inputs.