A sample of 226 Swedish high school teachers from various knowledge domains completed self-report measures of intelligence regarding implicit theories and scientific theories of intelligence. A mixed ANOVA showed that teachers from language, social science and practical disciplines had a significant preference for an incremental theory of intelligence compared to an entity theory of intelligence whilst the teachers in mathematics did not. One of the conclusions was that entity theories of intelligence may be more pronounced among teachers in mathematics. Second there is a significant relation between naive beliefs in intelligence as fixed and inborn, entity theories, and the scientific g-factor theory. Last, it was the oldest and most experienced and youngest and least experienced teachers who preferred an entity theory of intelligence the most. (Contains 1 note and 4 tables.)