The study seeks to examine how different aspects of internal marketing contribute to improving the effectiveness of salespeople in Saudi telecommunication companies. To accomplish this, a descriptive-analytical approach was utilized. A questionnaire consisting of 40 items was developed by the researcher as a data collection tool. A purposive sampling method was employed to distribute the questionnaire to 500 sales sector employees in Saudi telecommunication companies. Out of the distributed questionnaires, 417 were collected and considered suitable for analysis. The data collected was analyzed using appropriate statistical methods with the assistance of SPSS software. The study yielded significant findings, including an average score of 3.828 for the “internal marketing” dimension as perceived by the study participants, and an average score of 3.78 for the “salesperson efficiency” dimension. The results indicated a statistically significant impact of both the combined and individual dimensions of internal marketing (employee empowerment, training, incentives, and internal communication) on enhancing the efficiency of salespeople in Saudi telecommunication companies. The study recommended that Saudi telecommunication companies focus on continuously developing the “incentives” dimension within their internal marketing strategies due to its significant influence on salespeople's efficiency. This can be accomplished by providing collective and individual material and moral incentives to the sales team. To optimize the effectiveness of salesmen, it is crucial to prioritize their training, as it has been found to have a lesser effect on their efficiency compared to other aspects of internal marketing. Educating salesmen on the significance of training is a key step in achieving this. Additionally, efforts should be made to improve salesmen's efficiency through internal communication, empowerment, and granting them more decision-making power and autonomy.