This study investigated the effect of emotional intelligence on organizational performance of telecommunication firms in Nigeria. It focused on ten (10) selected telecommunications firms in Delta State. The objectives of the study were to determine the effect of self-awareness, self-regulation on organizational performance of employees of telecommunication firms. The study adopted descriptive survey research, and responses from the respondents were generated with a five point Likert Scale questionnaire. A total of one hundred and seventy-one (171) copies of the questionnaire were administered to employees of ten (10) selected telecommunication firms in Delta State, Nigeria. From the one hundred and seventy-one (171) copies of the questionnaires that were administered, one hundred and twenty-three (123) were retrieved and properly filled. Data obtained were analyzed using descriptive and inferential statistical tools. The multiple regression result revealed that there is significant relationship between self-awareness, (p-value = 0.004 < 0.005), self-regulation (p-value = 0.020 < 0.05) and organizational performance. The study concludes that emotional intelligence has a positive significant effect on organizational performance in the telecommunications firms. Based on the finding, the study recommends that self-awareness skills of leaders should be encouraged to improve subordinates’ work attitude. The study provides a model of motivation of workers that shows how the various dimensions of motivation can improve organizational in the telecommunication sector.