The solid–liquid equilibrium (SLE) phase diagrams of anthracene + 2-phenylimidazole, anthracene + 4,5-diphenylimidazole and anthracene + 2,4,5-triphenylimidazole, were measured using differential scanning calorimetry (DSC). These systems formed a simple eutectic diagrams. The eutectic composition in different mixtures has been determined by the Tammann's method. The curves of the liquidus in the ideal case were calculated and represented. The {anthracene + 2-phenylimidazole} system exhibits more non-ideal behavior than the two others. Thus, to illustrate the effect of steric hindrance, the eutectic composition and the eutectic temperature as a function of the phenyls number have been represented.