AgI-Al2O3 composites were prepared using sol-gel-derived Al2O3 aerogels and xerogels. The addition of Al2O3 aerogel or xerogel to AgI enhanced the ionic conductivity. The conductivity at room temperature showed a maximum at the composition 0.4AgI .0.6Al(2)O(3) in both aerogel-containing and xerogel-containing composites and was 2.8 X 10(-3) S cm(-1) for the aerogel composite. The conductivity of aerogel-containing composites was larger than that of xerogel-containing composites for all compositions, suggesting that the pore size distribution of aerogels was more effective than that of xerogels for enhancing the ionic conductivity.