In this article, we report kindergarten student and teacher outcomes from a quasi-experimental evaluation of The Superkids, a systematic, phonics-based, comprehensive K-2 reading program. We recruited 23 kindergarten teachers to implement The Superkids program from a diverse, yet predominantly ethnic minority, group of classrooms from across the United States. We then employed a precise computerized matching methodology to derive a statistically equivalent comparison group of 20 control teachers who implemented their standard "business as usual'' core literacy program. Multilevel analyses of classroom-level effects of The Superkids revealed achievement advantages of more than 1/10 of a standard deviation, d = 0.11, to 1/4 of a standard deviation, d = 0.25, for the treatment group on the 5 subtests from the Stanford Achievement Test, 10th edition (SAT-10). Four measures of teachers' self-reported satisfaction with the core reading program used in their classrooms also revealed statistically significant advantages for Superkids of nearly three-quarters of a standard deviation, d = 0.72, to nearly 11/2 standard deviation units, d = 1.49.