The phase diagram of the EuBr 2 –KBr binary system was derived from DSC measurements. It exhibits three eutectics and three stoichiometric compounds. The first compound, K 2 EuBr 4 , melts congruently at 834K. The second one, KEuBr 3 undergoes a solid–solid phase transition at 810K and decomposes peritectically at 846K. The third compound, KEu 2 Br 5 , melts congruently at 880K. The composition of the three eutectic mixtures, x(EuBr 2 )=0.318, 0.433 and 0.789, respectively, were determined by the Tamman method. The respective eutectic temperatures are 829, 811 and 854K.Diffuse reflectance spectra of the pure components and their solid mixtures confirmed the existence of new phases exhibiting their own spectral characteristics, which may be related to the existence of above mentioned compounds in the system under investigation.