Implicit theories of intelligence (i.e., individuals' beliefs about the nature of intelligence, such as whether it is fixed or changeable) are important because they are related to individuals' behaviors and their beliefs in other areas (Sternberg, 2000). Implicit theories of intelligence are especially important in educational settings because students who view intelligence as something that can be changed tend to be more academically motivated and perform at higher academic levels than students who view intelligence as a fixed, unchangeable trait (Blackwell, Trzesniewski, & Dweck, 2007; Dweck, 1999). Much of the research related to implicit theories of intelligence has focused on investigating the beliefs of students. As a result, there is less research related to teachers' beliefs about intelligence. Teachers' conceptions of intelligence are important, however, because they have been found to affect students' beliefs about intelligence (Oakes, Wells, Jones, & Datnow, 1997; Watanabe, 2006), which in turn impacts students' motivation and achievement (Dweck, 1999). The purpose of this study is to contribute to the literature on implicit theories of intelligence by investigating the nature of preservice and inservice teachers' intelligence beliefs. (Contains 2 tables.)