Ag/AgCl nanocomposite is a versatile plasmonic photocatalyst studied extensively in recent times; however, its stability and evolution through catalytic runs have not been explored. A simple protocol for the in situ fabrication of nanocomposite thin films of Ag/AgCl in poly(vinyl alcohol) (PVA) is developed. AgCl-PVA film formed first is photo-irradiated in water to form Ag/AgCl-PVA; the fabrication is monitored through spectroscopy, microscopy and chemical analysis. Photocatalytic application of Ag/AgCl-PVA is demonstrated by its efficient degradation of methyl orange under low power visible light; the 'dip catalyst' nature of the film facilitated several efficient reuses. Significantly, the thin film form facilitated rigorous monitoring of the composite through the reuse cycles; a small but steady evolution of the AgCl to Ag is revealed. In addition to the facile in situ fabrication of an efficient nanocomposite thin film plasmonic photocatalyst, the study presents a convenient approach to evaluate its fate through multiple reuses. (C) 2016 Elsevier Ltd. All rights reserved.