Building on and extending earlier research on student selfconcepts and studies investigating teachers working with students with social, emotional, or behavioural difficulties, disorders, or disturbance, this longitudinal study examined teacher self-concepts in relation to their willingness to teach challenging students in mainstream classrooms. In the current study, "challenging students" refer to those who may pose a challenge to the teacher, either behaviourally or academically. Statistical measures included analysis of variance, correlation analysis, path analysis, and commonality analysis. Survey data collected from 108 participants at three different time points consistently showed that affective self-concept was a stronger predictor than cognitive self-concept of teachers' willingness to teach challenging students. This study affirms and extends self-concept research by showing that the affective dimension of teacher self-concept is a better predictor of choice indicators than the cognitive dimension. The study also highlights the importance of developing and sustaining a strong sense of professional enjoyment for teachers in facing challenging teaching environments.