It is well known that the immune response is blunted and underdeveloped in the premature infant, but human milk supports the infant's growth, function, and effectiveness. Thus, own mother's colostrum (OMC) administered oropharyngeally has potential to deliver oral immune therapy (C-OIT) even before enteral feedings have begun. Colostrum interacts with lymphoid tissue in the oropharynx and gut. Colostrum as oral immune therapy is delivered by swabbing the cheeks in the first days of life. Little formal study has evaluated its effectiveness. However, small studies demonstrate that it is a practice that is safe, feasible, and well tolerated even by the smallest premature infants. Encouraging preliminary evidence supports the effect of C-OIT to reduce the time to full enteral feedings. Effects on other outcomes is unclear, in part because existing studies are underpowered to detect significant differences on outcomes like necrotizing enterocolitis, sepsis, and death. Another limitation in the evidence base is that adherence to the intervention and the number of doses of colostrum infants received in the studies is not consistently made clear. More well-designed studies are needed to demonstrate the impact on neonatal complications and how C-OIT supports the infant's immune development. Quality improvement and time series reports of differences pre- and postimplementation of OMC given orally should minimally include statistics for adherence to the intervention and/or the number of doses an infant received as a covariate. Even so, OMC is an immune therapy that poses little risk yet offers likely cost-effective benefit for vulnerable infants.