This study investigated the answer changing behavior of the Iranian university students and its relationship to the academic course, gender, and field of study. 362 students at the University of Isfahan took part in the study. 76 English language teachers were also surveyed for their attitude toward answer changing on MC tests. The results indicated that 42.11% of the teachers had a negative attitude toward answer changing as they believed that the first answer selected is intuitively the best one and should not be changed. The results also indicated that answer changing would basically have positive effects on the total test scores. It was found that 63.09% of the answer changes were beneficial (from Wrong to Right choices). In contrast, 15.18% of the answer changes were negative (from Right to Wrong options), and 21.73% had no effect on the test scores (from Wrong to Wrong options). As for the effect of gender, no significant difference was found between males and females. Concerning the effect of academic course, the only significant difference lay in the number of Right to Wrong changes. Finally, it was found that field of study would make a difference only when Right to Wrong changes were considered.