One-step wet chemical synthesis of an Eu2+-activated Li2Sr2Al2PO4F9 nanophosphor is described. Formation of the compound was confirmed by X-ray diffraction and characterised by photoluminescence and transmission electron microscopy (TEM) technique. TEM observation showed an average diameter of about 50 nm for the particles with a spherical-like morphology. The prepared powders exhibited intense blue emission at the 430 nm owing to Eu2+ ion by Hg-free excitation at 355 nm, that is, solid-state lighting excitation. Hence, the availability of such a nanophosphor will significantly help in the development of blue-emitting solid-state lighting applications.