The semi-organic crystal of 4-carboxyanilinium perchlorate monohydrate is grown by slow evaporation method at room temperature. The single crystal XRD study of title crystal ensures that the grown crystal is in P21/c space group with monoclinic structure. The PXRD analysis shows crystalline nature of the title crystal. The various functional groups present in the crystal are analyzed by using the FT-IR and FT-Raman spectroscopy techniques. The 4- carboxyanilinium cation and perchlorate anion is linked through the hydrogen bonding network which is confirmed by both spectroscopy techniques. The optical band gap is determined by using the UV-Visible spectroscopy analyzes and this study also reveals that the grown crystal has high transparency in the entire visible region. SEM with EDX analyzes shows that the grown crystal has smooth surface and well defined shape. The elemental composition study confirms the presence of elements in the 4-carboxyanilinium perchlorate monohydrate crystal. The antimicrobial activity of title crystal was tested against the five different micro-organisms by disc diffusion method. This result reveals that the complex crystal has more antibacterial effect than the parent crystal of PABA.