Polyacrylonitrile-based Zn-Al layered double hydroxide composites (PAN/LDH) have been synthesised with different LDH content by in situ polymerisation technique. The nanocomposites were systematically studied by Fourier transform infrared spectroscopy, X-ray diffraction (XRD), thermo gravimetric analysis (TGA), field emission scanning electron microscope (FE SEM), high resolution transmission electron microscopy (HRTEM), energy dispersive spectroscopy (EDS) and antibacterial activity measurement. The successful formation of exfoliated nanocomposite was inferred from the XRD patterns and HRTEM images. The thermal decomposition of PAN was enhanced upon nanocomposite (PAN/LDH) formation. The antimicrobial activity of PAN/LDH nanocomposites is evaluated for antibacterial activity against some clinically important bacterial pathogens and the bacterial growth is monitored at different percentage of LDH. The PAN/LDH composites displayed considerable antibacterial activity, on the contrary the virgin PAN did not possess any antibacterial activity. The likely electrostatic interaction among LDH layers with charged surface of bacterial cell is assumed to be responsible for antimicrobial activity. The prepared nanocomposite has appreciable thermal stability in combination with antibacterial activities by which the material is suitable for packaging and fabrication in textile application.