Plastic is the most diverse kind of material that is used and being produced in large quantities today. Wastes out of them pose a great threat to the environment especially global warming by emitting harmful gases. These scenarios prompted the researchers to use them as additives in a concrete mixture, and to determine if they have significant effect on the flexural strength of the concrete. Experimental method was used in this study since it is the appropriate method to determine whether thermoplastic as fiber additive in concrete can increase the flexural strength of the material. 1:2:4 concrete mixtures were used in the two-sets sampling having three trials each. First set of samples did not contain any plastic while the second set of samples included plastic. These were shredded to approximately 0.2”x1.” Rectangular 6”x6”x24” wooden moulds were used. The testing was done after the 14th day of curing and the results were analyzed using arithmetic mean and ttest. The t-test results revealed that the flexural strength of concrete with thermoplastics was significantly higher than the flexural strength of concrete without thermoplastics. Thus, the experiment validated that addition of thermoplastics to concrete increases the flexural strength of the concrete.