The ability of yeast cells to survive during the stationary phase of growth is a highly desired feature for industrial yeast bioprocesses, and for aging research. Chronological lifespan (CLS) is the duration of viability during stationary phase. For CLS estimation; the conventional, quantitative CLS method based on viable cell counting is used which is labor-intensive for testing a high number of strains. Thus, a practical screening method is required to identify long-lived strains among a great number of strains. It was aimed, first, to improve a semi-quantitative CLS method to allow an efficient, comparative and reliable CLS estimation of strains with significantly different cell densities during the stationary phase of growth. The second aim was to determine the CLS of two stress-resistant Saccharomyces cerevisiae strains. An initial cell density adjustment step was introduced to a semi-quantitative CLS method based on yeast spot assay. This improved method was verified by the quantitative CLS method. The improved semiquantitative method can be used as a reliable screening method for longevity studies with high sample size. Additionally, oxidative stress-resistant and ethanol-tolerant S. cerevisiae strains have prolonged CLS, suggesting their use in industrial applications and aging research.