This study is an exploration of the personality traits of Yemen EFL undergraduates and the effects these traits overshadow on their academic achievements. Two instruments were used to collect the data: a personality questionnaire and performance record analysis. The former measured the personality and the latter was used to measure accumulative academic achievement throughout their undergraduate studies. The investigation was carried out by comparing the personality scores of 50 senior EFL learners against their scores of academic performance. The study showed (a) a positive correlation between personality and English performance, (b) insignificant differences in the participants’ performance based on gender variable, and (c) extraversion and agreeableness‒among the Big Five Personality traits‒ accounted for a statistically significant amount of variance in EFL achievements. The study brings to the foreground some pedagogical implications and venues for further research.