Single crystals of 5Bi0.9Er0.1(MoO4)4 were grown from stoichiometric melts by the usual Czochralski technique. The crystal belongs to trigonal system, with space group R3m , z=1.5, and cell parameters a=6.029?, c=20.823? (hexagonal setting). Due to the layered structure, the crystals exhibit easy cleavage along (0001) face. The room temperature absorption spectrum of 5Bi0.9Er0.1(MoO4)4 consists of severalbands characteristic for the rare earth ions in crystals. The spectrum is dominated by three absorption bands associated with transition from the ground 4I15/2 level of Er3+ to the 4G11/2, 2H11/2 and 4I13/2 levels, Details of room temperature emission Spectra Corresponding to the 4I13/2→4I15/2 transition are also given.