Procuring requested relief items, while ensuring an available budget, is an essential task in humanitarian logistics. Humanitarian organizations (HOs) are facing difficult decisions about procurement portfolios (i.e., prepositioning-versus-emergency procurement) and fundraising strategies. We develop a two-stage newsvendor model in the context of a leader–follower game between a representative HO (the leader and donors (the follower)to characterize their interactions. In our model, the HO decides on the prepositioning level for disaster preparedness under uncertainty, while the fundraising expense is determined on the disaster response phase. Our research compares a budget-constrained case with a budget-unconstrained benchmark case. Furthermore, we discuss the trade-off between the efficiency (i.e., maximizing HO’s expected budget) and effectiveness (i.e., maximizing expected demand fill rate) of procurement and fundraising operations. Our numerical analysis reveals that the budget-unconstrained environment would provide the HO with misleading managerial insights into procurement portfolios—overemphasis on prepositioning. Further, an effective fund-raise mechanism that could raise donors’ motivation for donations would reduce prepositioning. We also observe that prepositioning cannot guarantee to achieve the highest operational effectiveness (demand fill rate) due to the loss of fundraising opportunities. Research implications and managerial guidelines are proposed.