Single ferroelectric Pb(Sc1/2Ta1/2)O-3 crystals of perovskite structural type were obtained by the high temperature solution growth (HTSG) method. The refractive index was measured by the prism method at 10 selected wavelengths and the dispersion in the visible spectral range was calculated by Sellmeier’s formula. Optical transmission and reflection spectra were measured and the absorption coefficient alpha was determined in the visible range. Using the calculated alpha(h upsilon) dependence, the alpha(1/2)(h upsilon) function was plotted and it was used to determine the bandgap width and characterize the fundamental absorption edge.