The international community has seen a dramatic increase in the complexity of aid operations, with increasing numbers of donors participating in humanitarian aid endeavors. Therefore, it is essential to determine factors that contribute to successful aid delivery. In an effort to guide more effective and efficient aid operations, this study investigated organizational culture in three distinct types of humanitarian organizations: (a) the U.S. military, (b) the International Federation of the Red Cross, and (c) a sampling of local and indigenous non-governmental organizations. Being a relatively unexplored area, this study took an exploratory approach, utilizing qualitative methods to analyze humanitarian aid efforts. Organization types were evaluated as individual case studies, consisting of in-depth interviewing, naturalistic observer studies, and reviews of records and reports. The study utilized the Hofstede Cultural Orientation Model as a theoretical framework to systematically compare organizational cultures. Overall, the study lends support to the general principle that organizational culture plays an important role in the delivery of humanitarian assistance. Differences in group culture emerged and were indicative of the varied cultures of prominent aid organization types. A systematic cross cultural comparison of the three aid delivery types indicate that the basic assumptions and beliefs that guide humanitarian organizations vary greatly, affecting how organizations act and interact with others. Findings yielded support for collaborative efforts, while also highlighting differences in policy and practice. The study also identified areas of cultural divergence, allowing for a clearer understanding of differing aid delivery methods, organizational decision making, and the affect on collaboration. Findings stress the importance of bridging organizational differences more effectively. These findings come almost ten years after Hurricane Mitch, countless pledges to humanitarianism and the determination of the need for collaboration. Yet results indicate that the international community continues to grapple with many of the same issues, highlighting the need for better communication, unity of effort, and strengthening of relationships between the military and the NGO community. Findings also suggest the need for further research, changes in policy and practice and a call to action.