We have studied the dielectric properties of a new, cubic pyrochlore-type solid solution Bi(1.6-0.8x)YxTi2O(6.4+0.3x) (0.03 < x < 2). The single-phase nature of the pyrochlore solid solution was determined using X-ray diffraction and scanning electron microscopy. We found that at room temperature and 1 MHz the pyrochlore solid solution exhibited values of the dielectric constant epsilon between 127 and 64, and low dielectric losses, tan delta, of < 6 x 10(-3). The temperature coefficient of the dielectric constant tau(k) is, however, strongly dependent on the composition. Below room temperature dielectric relaxation phenomena were observed for the compositions with low x values.