The purpose of this study was twofold: (a) Examine successful choral director beliefs about warm-ups and their successful practices in conducting warm-ups, and (b) examine the relationship of musical background, choral training and music teaching style of high school choral directors upon these beliefs and practices. Subjects were 365 high school choral directors from 28 states. Data were analyzed using descriptive analysis, correlation analysis, multivariate analysis of variance and multiple regression. Results indicated choral director's beliefs and practices differ as a function of musical back-ground, demographic characteristics, choral conducting training, and music teaching styles. Specifically, warm-up beliefs were predicted by knowledge of vocal health and variety of warm-ups. Conversely, those who relied on the warm-up time for discipline and focusing attention showed a significant negative relationship with their philosophy. From multiple regression analysis, doing choral warm-ups accounted for one-third of a director's overall success, predicted by 10 variables: (a) experience, (b) education, (c) teaching style teacher-directed performance, (d) teaching style deep-student learning, (e) warm-up literature and procedure, (f) planning warm-ups (g) warm-up content, (h) prior choral experience and piano background, (i) a foundation in music, and (j) a developed philosophy of choral warm-ups. However, having a philosophy about warm-ups did not predict successful teaching practices.