Genotypic variation in postharvest flower longevity was determined for 63 Asiatic lily hybrids (Lilium L.). The reliability of standardized test conditions for longevity screening was also examined. Improvement of lily flower longevity by breeding appears feasible. Considerable genotypic variation in individual flower longevity was obtained and estimates of the degree of genotypic determination were high. The rank order of the genotypes with respect to individual flower longevity was similar between years using standardized test conditions. Screening results for flowers forced in a growth chamber were similar to those obtained in a greenhouse. No plant traits suitable for indirect selection on flower longevity were detected.