In a survey study, we investigated teacher attitudes toward acceleration and accelerated students in the Netherlands. Teachers (N = 334) from 31 secondary schools gave their opinion about gifted education and acceleration, and evaluated statements about accelerated students. Most teachers considered a special approach for gifted students advisable and acceleration a useful intervention. Teachers' opinions about accelerated students' social competence, school motivation and achievement, emotional problems, and isolation were qualified by the quantity and quality of prior experience with accelerated students and by their opinion on acceleration in gifted education. In a subsequent intervention study, we examined whether specific information on acceleration and giftedness changes teachers' attitudes toward accelerated students. Teachers who attended the information meeting and received written information expressed more positive opinions about accelerated students' social competence and school achievement and motivation and less negative opinions about emotional problems after intervention. Implications for gifted child education are discussed. (Contains 4 tables and 6 endnotes.)