The present study was designed to investigate teacher misbehaviors as learning demotivators across four cultures: the U.S., China, Germany, and Japan. Three major findings were reported: (1) teachers across cultures all were perceived to misbehave infrequently, with only slight variations found across cultures; (2) teachers across cultures were perceived to engage in similar misbehavior tendencies. Overall, incompetence was the most common form of teacher misbehaviors, and some of the most frequently reported teacher misbehaviors were similar across cultures; and (3) teacher misbehaviors were associated with learning demotivators pan-culturally and within each culture, but they differed in the magnitude as predictors, explaining 8%–39% of the variance in student demotivation across cultures. Among the three dimensions of teacher misbehaviors, incompetence was the greatest source of demotivation within and across cultures.