This study intends to examine the influence of self-efficacy on the ethical behavior of sales force along with moderating effects of gender in the telecom sector at Pakistan. In addition, it also examines the impacts of self-efficacy and ethical behavior on the service quality in telecom sector. It assesses the mediating role of ethical behavior on the relationship between self-efficacy and service quality. This study has collected data through selfadministered questionnaire from the sales representatives and managers in the telecom sector at Khyber Pakhtunkhwa, Pakistan. The collected data were analyzed using correlation statistic and stepwise regression. The results have shown a positive significant effect of self-efficacy, while gender has positive but insignificant effect on the ethical behavior of sales force. In addition, gender has moderating effects on the relationship of self-efficacy and the ethical behavior. Self-efficacy and ethical behavior have also positive significant effects on the service quality. Additionally, ethical behavior has mediating role between self-efficacy and service quality. This study is addressing a need to examine the influence of self-efficacy and the ethical behavior on the service quality of sales force in undeveloped and less educated areas of Pakistan, which is useful and helpful to explore understanding in the nature of defined variables in the eastern culture of Pakistan where male gender is more dominant.