The private higher education sector in developing countries is challenged with high turnover, which has resulted in lowered sustainable competitive advantage. The resource-based theory considers strategic resources as a vital source to achieve a competitive advantage among its competitors. We argue that staff retention is a key factor to address these issues; therefore, the impact of internal marketing strategies on staff retention is examined through a sample of 352, collected from private higher education institutes in Pakistan, using close-ended questionnaire on 5-point Likert scale. The results highlight that economic, social and repute factors of internal marketing promote favorable employee attitude. Despite psychological contract violation, economic factor emerges as a key factor for staff retention. The results provide deep insight into higher education sector regulator as well as HR managers in private higher education universities to improve longer staff retention for sustainable competitive advantage while ensuring education quality.