The interest felt towards a profession can have influence on many aspects of one's academic life including fulfilling the college degree requirements, the decision to change the subject being studied, satisfaction with the learning process and academic success. This study investigates the extent to which the pre-service teachers of biology are interested in their teaching profession. The study is of a descriptive nature. The study sample of the research comprised 137 teacher trainees studying in the Department of Biology Education at Hacettepe University in the 2006-2007 Academic Year. The data collection tool used was the Teaching Profession Interest Scale developed by the present researchers. The scale was developed based on person-object theory. The instrument consists of four dimensions, namely emotional dimension, values-related dimension, epistemic dimension and intrinsic motivation dimension. The results of the research indicate that the professional interest of the biology teacher candidates is high, that the interest does not exhibit any differences vis-A-vis gender in the dimensions other than the epistemic factors and that the professional interest is at the highest level among final year students. Furthermore, a statistically significant relationship is identified between professional interest and academic success.