Pyrochlores Bi_1.6Ho_ x Ti_2O_7 – δ and Bi_1.6Mg_0.1Ho _ x Ti_2O_7 – δ, where x = 0, 0.01, 0.05, and 0.1, and Bi_1.5Ho_ x Ti_2O_7 – δ, where x = 0.25 and 0.5, have been synthesized and their structural, optical, and luminescence properties have been studied. As a result of analyzing the data obtained experimentally and the available theoretical data, it is shown that the intrinsic luminescence of the samples is due to the O2 p ↔ Bi6 p and Bi6 s ↔ Bi6 p electron transitions and the impurity luminescence is due to the f – f transitions in Ho^3+ and the O2 p → Ho^3+ charge transfer.