The study developed and tested a model to examine the influence of personality traits and motivational needs on task performance behavior of university teachers in Pakistan. Using convenience sampling technique, 650 structured questionnaires were administered to faculty members in Pakistani universities. The findings showed that core self evaluations influence acquired_x0002_motivational needs that is need for power has positive impact on task performance behaviors than need for achievement, whereas need for affiliation has no impact on task performance behavior. This study has added to existing literature by introducing motivational needs as an important facilitator in the link between core self-evaluations and task performance behavior. This is among first studies that has incorporated core self-evaluations within the acquired needs framework particularly in the Asian context. Major implications of the study were also discussed.