Implementing an Australian National Curriculum will require targeting both teachers and preservice teachers. Classroom teachers in their roles as mentors are well situated for developing preservice teachers. This mixed-method study presents mentors' reports on their mentoring of primary preservice teachers (mentees) in mathematics (n=43) and science (n=29). Mentors claimed they mentored the teaching of mathematics more than the teaching of science; 20% or more indicated they did not provide mentoring practices for 25 out of 34 survey items in the science and 9 out of 34 items in the mathematics. Mentors also claimed that professional development on effective mentoring can enhance their skills. Implementing an Australian National Curriculum necessitates professional development for mentors on effective mentoring practices in order to increase the quality and quantity of mentoring for enhancing preservice teachers' practices. (Contains 6 tables and 2 figures.)