Context: Approximately 22 people die each day in the United States as a result of the shortage of transplantable organs. This is particularly problematic among Spanish-dominant Hispanics. Increasing the number of registered organ donors can reduce this deficit. Objective: The goal of the current set of studies was to conceptually replicate a prior study indicating the lack of utility of a lone, immediate and complete registration opportunity (ICRO). Design and Setting: The study, a quasi-experimental design involving a total of 4 waves of data collection, was conducted in 2 different Mexican consulates in the United States. Guided by the IIFF Model (ie, an ICRO, information, focused engagement, and favorable activation), each wave compared a lone ICRO to a condition that likewise included an ICRO but also included the 3 additional intervention components recommended by the model (ie, information, focused engagement, and favorable activation). Participants: Visitors to the Mexican consulates in Tucson, Arizona, and Albuquerque, New Mexico, constituted the participant pool. Main Outcome Measure: New organ donor registrations represented the dependent variable. Results: When all 4 components of the IIFF Model were present, approximately 4 registrations per day were recorded; the lone ICRO resulted in approximately 1 registration every 15 days. Conclusion: An ICRO, without the other components of the IIFF Model, is of minimal use in regard to garnering organ donor registrations. Future studies should use the IIFF Model to consider how the utility of ICROs can be maximized.