Children are considered a vulnerable population and have traditionally been excluded from research studies. This exclusion of children in general, and neonates in particular, from clinical research hampers the development of safe and effective therapies in this population. However, research involving children (including infants) is essential to guide therapy and optimize care. Neonatal research is complex, time intensive, difficult and expensive to conduct, and raises some unique ethical considerations. The complexity of research in this population is highlighted by the fear of causing harm to fragile sick infants which has led to the creation of special regulations on the degree of risk exposure permissible in research involving infants. This is further compounded by the inability of infants to provide informed consent or assent and the reliance on obtaining surrogate consent from parents who may themselves be vulnerable and overwhelmed by their infant's illness and the amount of information provided to them. In this review, we discuss the evolution of ethical regulations related to research, the justification for research in infants, and some of the ethical nuances of research in this population.