Water-holding stone vases were sampled in 4 central Florida cemeteries to compare the prevalence of mosquitoes in containers with and without metallic liners. Overall, immature mosquitoes were found in more than 60% of the vases lacking liners and in more than 50% of the vases with aluminum liners. Significantly fewer vases with copper liners were positive for mosquitoes. High mortality and a lack of development were observed in a field test involving the introduction of Aedes aegypti larvae into stone vases with copper liners.