Diagnostic errors remain understudied in neonatology. The limited available evidence, however, suggests that diagnostic errors in the neonatal intensive care unit (NICU) result in significant and long-term consequences. In this narrative review, we discuss how the concept of diagnostic errors framed as missed opportunities can be applied to the non-linear nature of diagnosis in a critical care environment such as the NICU. We then explore how the etiology of an error in diagnosis can be related to both individual cognitive factors as well as organizational and systemic factors - all of which often contribute to the error. This multifactorial causation has limited the development of methodology to measure diagnostic errors as well as strategies to mitigate and prevent their adverse effects. We recommend research focused on the frequency and etiology of diagnostic error in the NICU as well as potential mitigation strategies to advance this important field in neonatal intensive care.