The culture of International Organizations is an amalgam of National and Organizational impacts on staff relationships which affect organizational efficiency and effectiveness. The research for this dissertation took place within the World Health Organization (WHO) and followed a qualitative process based on Grounded Theory. Data was obtained from several hundred WHO staff members who participated in workshops, interviews, focus groups and an online survey. A recurring theme from the data revealed that culture operated as a kind of paralysis, preventing people from expressing themselves comfortably, making it difficult to know what behavior was acceptable or expected and suppressing the ability to be assertive when necessary-all of which dampens the potential of an internationally diverse workforce. National Culture was examined following Hofstede’s “4D” dimension of Individualism / Collectivism, Power Distance, Uncertainty Avoidance and Masculine /Feminine. Organizational Culture was examined from traditional functionalist theory, the impact of Haas’ research on Epistemic Communities and Barnett and Finnemore’s Bureaucratic Actor Models of structure and dysfunction. The research also examined the impact of National and Organizational Culture on communication and relationships among staff and management during meetings and negotiations. A significant finding is that Organizational Culture overrides National Culture in staff-to-staff relationships, creates a top down hierarchical environment that impacts decision-making leading to a pattern of bureaucratic normalization that fails to take advantage of cultural and gender diversity. The dissertation recommends that WHO and international organizations in general institute a process of discovering their cultural landscape as a resource and a potential of untapped power with which to further their missions and objectives. A further recommendation is to view cultural differences through a lens of “Consilience” where National, Organizational and Communication Cultures converge to produce holistic new approaches in research, analysis and practice in order to benefit both efficiency and effectiveness as well as to improve international integration.