Antimicrobial textiles have played an increasingly important protection role in the medical field. With this aim, Schiff bases and nanometal complexes on the cotton fabric were in situ synthesized for achieving the conventional cotton fabric’s highly efficient and durable UV protection and antibacterial properties. Herein, a new Schiff base derived from the condensation reaction of 2,4-dihyroxybenzaldehyde with p-amino aniline was synthesized. Co, Ni, Cu, and Zn complexes of the Schiff base were also prepared and characterized by UV-Vis, Fourier-transform infrared spectroscopy, ¹HNMR, ¹³CNMR, elemental analysis, and thermal analysis. The modified cotton fabric was also characterized via X-ray diffraction, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), transition electron microscope (TEM), and Energy Dispersive X-Ray Analysis (EDX). Moreover, the microbial, UV protection, and tensile strength of the samples were investigated. The antimicrobial was studied against Gram-positive bacteria, Gram-negative bacteria, and fungal strains. Modified cotton fabric exhibited highly antibacterial activity in contrast with fungal activity. These results depended on the Schiff base and the type of metal complex. The results also show that the cotton fabric modified by in situ nanometal complexes provides excellent UV protection.