This paper presents the results concerning the photoluminescence spectra of 53ZrF 4 -20BaF 2 -2LaF 3 -2YF 3 -3AlF 3 À(20Àx)NaF-xEuF 3 multi-component heavy metal fluoride glasses with the Eu 3+ =0.2, 0.4, 0.8, 1.0, 1.2 and 1.4 mol% in order to evaluate the threshold of concentration quenching (C q ¼ 1 mol%) which corresponds to the concentration limit clearly revealing an intense red emission ( 5 D 0 -7 F 2 at 614 nm) from such a luminescent glass. A bright red emission was observed by the naked eye from these materials under an UV source. The dopant ion concentration quenching on the emission behaviour has been ascribed to cross-relaxation and dipole-dipole interactions in the glass matrices. Influence of changes in active ions content (N Eu 3+ Â 10 22 cm À3 ) on the values of interionic distance (r i ( A) and polaron radius (r p ( A) has been verified. The photoluminescence spectra are constituted essentially by six emission transitions of ( 5 D 0 -7 F J=0,1,2,3,4,5 ) between the wavelengths of 575 and 720 nm. We have also investigated the dependence of emission intensities and lifetimes on various pump wavelengths and identified a more suitable excitation line at 394 nm, which belongs to the transition 7 F 0 -5 L 6 of Eu 3+ ion.