Adoptions of Black children by White parents in the United States are rapidly increasing and are a frequent transracial adoptee-parent combination. With the prevalence of these adoptions, questions arise about White parents’ capability to promote the healthy racial-ethnic identity of their adopted Black child(ren). This study examined if White parents’ knowledge of racial-ethnic identity development impacts their intentions to promote their adopted Black children’s racial-ethnic identity in the context of the theory of planned behavior (TPB). White parents who have adopted, or were in the process of adopting, Black child(ren) (n = 199) completed measures examining their knowledge of racial-ethnic identity development and their attitudes toward, perceived subjective norms for, perceived behavioral control of, and intentions related to engaging in racial-ethnic socialization. Parents’ intentions to engage in racial-ethnic socialization were positively correlated with their attitudes toward, subjective norms for, and perceived behavioral control of racial-ethnic socialization. Knowledge did not predict parents’ intentions to engage in racial-ethnic socialization above and beyond the components of the TPB. Finally, parents who perceived greater subjective norms for and greater behavioral control of racial-ethnic socialization reported greater intentions to promote the racial-ethnic identity of their adopted child(ren), and these relationships were particularly strong among parents with relatively low knowledge. Consistent with ideas in the TPB, White transracial adoptive parents’ knowledge of racial-ethnic identity development (alone) may be neither necessary nor sufficient in predicting intentions to engage in racial-ethnic socialization.