Using data from 23 statistics instructors and 1,924 students across 11 post-secondary institutions in the United States, we employ multilevel covariate adjustment models to quantify the sizes of instructor and instructional effects on students' statistics attitudes. The analysis suggests that changes in students' statistics attitudes vary considerably across statistics instructors. Instructor-associated changes in students' statistics attitudes are positively associated with instructional practices most proximal to tasks involving data as well as with instructors' attitudes toward teaching their statistics classes. Moreover, instructor-associated changes in students' statistics attitudes are positively related to changes in students' expected grades. These findings lend support to previous qualitative findings about links between certain dimensions of teaching practices and students' statistics attitudes.