Calcium borotellurite glasses, doped with 0.25 mol.% of Sm2O3, were prepared to investigate the influence of TeO2 content in their properties. The samples were prepared by a melt-quenching method, with TeO2 varying from 9 mol.% to 51 mol.% and characterized by volumetric density, optical absorption, refractive index, luminescence and radiative lifetime. The results are discussed as a function of TeO2 content. The increase of TeO2 concentration increases the volumetric density and refractive index. The optical absorption spectra present peaks characteristic of Sm3+ ions. The most intense absorption peak was observed at 402 nm (6H5/2 →6P3/2 level). The increase of TeO2 content shifts the band edge to a longer wavelength, resulting in a reduction of optical energy band gap and an increase of Urbach energy. The luminescence spectra show four typical emissions of Sm3+ at 564 nm, 598 nm, 646 nm and 707 nm, corresponding to 4G5/2 →6HJ (J = 5/2, 7/2, 9/2, and 11/2) electronic transitions, respectively. The luminescence spectra present a reduction in their intensity with TeO2 increase, which occurs mainly due to the decrease of the number of ions per cubic centimeter. The luminescence intensity shows a decrease for all the samples with the temperature increase. The experimental lifetime of 4G5/2 →6H7/2 transition decreases with the increase of TeO2 content due to an increase of NBOs in the glass structure.