The implementation of teaching performance assessments has prompted a range of concerns. Some educators question whether these assessments provide information beyond what university supervisors gain through their formative evaluations and classroom observations of candidates. This research examines the relationship between supervisors' predictions and candidates' performance on a summative assessment based on a capstone teaching event, the Performance Assessment for California Teachers. The study, based on records for 337 teacher candidates over a 2-year period, specifically addresses the following questions: To what extent do university supervisors predict candidates' total scores? On which questions and categories of the assessment do supervisors most accurately predict their candidates' scores? Do supervisors predict scores more accurately for high- and low-performing candidates? The findings indicate that university supervisors' perspectives did not always correspond with outcomes on the performance assessment, particularly for high and low performers. (Contains 7 tables.)