<p>Composites are more commonly used in recent decade applications in various industries due to their low weight, higher tensile strength, high heat resistance, and design flexibility. This research paper discusses the effects of acid activation experimentally on the mechanical properties and surface roughness in case of carbon fiber reinforced polymer composites. This paper also discusses the role of graphene oxide (GO) and its effects on mechanical properties. The composite was fabricated using hand layup approach and the composite was produced with acid activated carbon fibers, epoxy resin and graphene oxide. These composites were observed using scanning electron microscopy (SEM) and tensile tests were conducted to measure performance. From the results it can be concluded that acid activation has a direct influence on the diameter and surface characteristics of carbon fibers when mixed with GO resin. This investigation helps us to improve the performance of carbon fiber reinforced composites by acid activation along with GO and epoxy for manufacturing of these composites for various applications. The study reveals that acid treatments, particularly with 1N HCl and 0.5N HNO₃, significantly enhance the tensile strength of carbon fiber epoxy composites by increasing surface roughness and fiber–matrix bonding. Additionally, graphene oxide incorporation further improves mechanical properties through enhanced wettability and interfacial adhesion due to functional group interactions.</p>