Aerosol spectral optical depths and size distributions evaluated from multispectral solar radiation extinction measurements from 1987 to 1996 were used to study the Pinatubo aerosol characteristics at a low latitude location, Visakhapatnam (17.7 degrees N, 83.3 degrees E) in India. The optical depths from June 1991 showed significant increase after the Mt. Pinatubo volcanic eruption. The volcanic aerosol optical depths have been obtained by subtracting the pre-volcanic mean aerosol optical depths from the corresponding monthly mean values during the post-eruption period. The optical depths of the Pinatubo aerosols have shown typical temporal and spectral variations, which were found to be significant for about two to three years after the eruption. The inversion of the spectral optical depths yielded a well-defined bi-modal size distribution for the first year after the eruption and it showed a broad monomodal form in the second year. The Pinatubo aerosol optical depths became very small by the end of 1993. The effective radius increased from 0.38 in June 1991 to 0.6 in November 1991 and it decreased from January 1992 onwards. The aerosol columnar mass loading decreased steadily from July 1991 onwards with an e-folding time of about 16.75 months.