Texas has apparently achieved great success in closing the gap between advantaged and disadvantaged students, at least in the lower grades. Texas students in all grades have made substantial gains on the Texas Assessment of Academic Skills (TAAS). The effect of TAAS-type accountability on student performance in the higher grades is important, since it is not sensible to claim that student outcomes are improving if the criteria for measuring academic achievement, the TAAS scores, do not lead to outcomes that count in life. This study reviewed the positive and negative claims for the Texas accountability system and examines, to the extent the data allow, the impact that TAAS has had on student educational attainment. Trends over time in statewide measures of test scores, progression through high school, high school completion, and college plans of high school seniors were analyzed. Then high school data were analyzed to estimate whether rising test scores are consistent with rising dropout rates. There has been increased retention in grade 9, but this trend began well before the implementation of the TAAS. Data show that Texas students have made real gains on the National Assessment of Educational Progress, which would appear to validate the claims that rising pass rates on the TAAS indicate real learning gains. However, other important indicators of educational success, namely high school progression and graduation rates, rose only slightly in the 1990s and then only in the most recent years. Rising TAAS score on the 10th grade test have had only a small impact on educational outcomes that count. Data do not support the claim that the documented increased retention in 9th grade is directly attributable to the new 10th grade TAAS examination.