There is a shortage of second/foreign language (S/FL) teachers in many parts of the world and the attrition rates are startling. The present study, grounded in social cognitive theory, investigates Canadian and US teachers' (N = 1065) sense of efficacy in teaching languages as it relates to teacher attrition. Findings indicate that S/FL teachers tend to leave the profession as a result of a lack of confidence to teach cultural knowledge as well as the classroom management issues that can arise. The research has implications for teacher-preparation faculty, professional development coordinators, and legislators. (Contains 2 notes and 2 tables.)