An investigation was made to study the suitability of using coal fly ash-stabilized sand mixtures as capping materials for sanitary landfills. Sand mixtures stabilized with 15 and 20 percent Class C fly ash were investigated. Compaction, permeability, unconfined compressive strength, freeze-thaw, and wet-dry tests were conducted on both mixtures. Results indicate that fly ash-stabilized sand blends can be used as capping materials in areas where fine-grained soils are not available. Data indicate that the 20% fly ash-stabilized sand mixture will yield a better performance than sand mixtures stabilized with 15% fly ash. Increased strength, reduced permeability, and increased resistance to freeze-thaw and wet-dry cycles are some of the benefits obtained by using the high fly ash content.