In light of the massive tsunami relief efforts that were still being carried out by humanitarian organizations around the world when this article went to press, this article points out a lack of human resources development research in international nongovernmental organizations (INGOs) and proposes a conceptual model for future empirical research. This article reviews the three related research areas of NGO history, volunteer training, and expatriate development; discusses the possibility of integrating the theory from these three areas; and finally builds a model for further empirical studies for expatriate training in INGOs. (Contains 1 table and 1 figure.)