The need for transplant exceeds the number of available organs. Antigen compatible organs are particularly scarce for African Americans because of their proportionately lower rate of donations. This study presents a measure of organ donation readiness. Examination of the factor structure and a test of weak invariance were conducted on cross-sectional (n = 2,662) and longitudinal data (n = 1,316) in a community-based sample of African Americans. A second-order structural equation was used to model the relationship between three latent factors. The results corroborate earlier research and confirm a second-order model structure consisting of 3 factors (Fear, Knowledge, and Action) in a set of 9 self-report items. The second-order model specification provided a good fit to the data. Social workers involved in organ procurement efforts and counseling of family members may find the instrument a useful tool for identifying readiness for organ donation among African Americans. (Contains 4 tables and 2 figures.)