Soft template mediated synthesis of Bi–In–Zn–S (BIZS) nanostructures were successfully achieved in poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) i.e. PEG-PPG-PEG at various temperatures with uniform size distributions. The newly synthesized BIZS nanostructures were characterized by powder XRD, IR, UV-vis, SEM, TEM, EDX, BET and TGA. The photocatalytic activities of the BIZS nanostructures were measured by the degradation of methylene blue under visible light (200 W tungsten lamp and sunlight).