This paper presents experimental results of S-glass fabric prepreg composite material to determine the compressive strength of uncertain S-glass fabric prepreg coupons along warp and weft direction at room temperature environment. A coupon is a small sample of the material under test that has been prepared in such a way that the failure mechanism will be representative of the larger production. Universal testing machine (UTM) was used for experiment. One of the hydraulic grips was fixed on the crosshead and the other grip was fixed on the hydraulic piston of the UTM. A load cell was provided on the crosshead for measuring the applied load. Uncertainty in the manufacturing process of S-glass is very important. Reducing the rejection rate of parts by selecting the right reinforcement, matrix and controlled process during the manufacturing process is very important which ensures the quality and performance of the manufactured parts as per application.