Dy₂Ce₂O₇ nanostructures were synthesized by the facile salt-assisted combustion method, with Dy(NO₃)₃·5H₂O and (NH₄)₂Ce(NO₃)₆ as dysprosium and cerium sources and various amino acids such as L-alanine, phenylalanine, glycine, valine and serine as fuel and capping agents in the presence of sodium chloride as a dispersing agent. Various amino acids as fuel in the presence of sodium chloride as a dispersing agent were employed to fabricate Dy₂Ce₂O₇ nanostructures for the first time. The as-prepared Dy₂Ce₂O₇ nanostructures were analyzed by energy dispersive X-ray microanalysis (EDX), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), Fourier transform infrared (FT-IR) spectroscopy, UV-vis diffuse reflectance spectroscopy and X-ray diffraction (XRD). According to the morphological investigations of the as-synthesized products, it was found that shape and size of the Dy₂Ce₂O₇ nanostructures are controlled by changing the amino acid type factor. The photocatalytic behavior of as-synthesized Dy₂Ce₂O₇ nanostructures was also evaluated by degradation of methyl orange dye as a water pollutant under UV light.