This paper explores early predictors of high school graduation and success. Employing 7th grade cohorts from three large California school districts (San Francisco, Fresno, and Long Beach), we investigate the role of several key middle school academic performance measures in identifying students' 11th grade academic performance, passing the California High School Exit Examination on the first attempt, and diploma receipt. We find that standardized assessments, timing of algebra, and course failures in middle school provide useful indicators of students' high school academic success. Our aim is not to identify any causal mechanism by which middle school achievement leads to high school success or failure, but rather to describe important associations that may aid policymakers and school leaders to develop strategies early in students' educational pursuit of the high school diploma.