The commercial use of biosynthesized metallic nanoparticles (NPs) is presently a wide area of research. With biosynthesis being an eco-friendly and convenient method, biologically synthesized nanoparticles can be used in the application and development of technologies. In this study, copper nanoparticles (CuNPs) were synthesized from a pineapple fruit extract and characterized by spectroscopic and microscopic techniques. The size of CuNPs obtained from scanning electron microscopy (SEM) images was found to be around 40 nm. The reduction of copper nanoparticles from CuSO4 was also visualized by colour change. The phytochemicals present in the pineapple extract are responsible for the reduction and capping of nanoparticles. The conductivity of the solution was 16.03 mS/cm, which implies that it can be used in applications requiring conductivity. Biologically synthesized metallic nanoparticles are quite stable in aqueous solution and can be widely used in various applications.