The claim that the incidence of school failure can be greatly reduced by increasing kindergarten entrance age from 57 to 60 months was investigated in three related studies. In the first study, subjects ranging in school entrance age from 57 to 68 months were drawn from five elementary schools in an urban lower socioeconomic area. A total of 114 nonrepeating kindergarten children were administered (1) cost-effective, highly reliable screening tests at the beginning of the kindergarten year and (2) several measures of academic performance at the end of the kindergarten and first-grade years. While first-grade testing involved subsamples, end-of-year promotion decisions were obtained for all children in the sample. The second study, a replication of the first, was similarly designed but included additional children from one middle class school. Some measures of school readiness were retained, some were excluded, and other measures were used. In the third study, interviews to determine the effect of background factors influencing school achievement were conducted with parents of 40 children in the replication study who were between 57 and 59 months old at kindergarten entry. Results of all three studies suggested that raising entrance age is likely to be less productive than initiating a psychometrically based screening program supplemented by intervention geared to the needs of the failure-prone child. (RH)