Feeding a mother's expressed breast milk to the wrong infant is a well-known misidentification error in neonatal intermediate care units (NICU) with potential harmful consequences for the neonate. In this study, we aimed to analyze the role of critical incident monitoring on detection and prevention of human breast milk confusions. The critical incident monitoring made us aware of this misidentification error on our NICU. Despite the implementation of system changes to make breast milk application clearer and safer, we failed to reduce the incidence of breast milk confusions.