Excipients are generally perceived as inert and pharmacologically inactive. Instead, serious adverse reactions have been reported in vulnerable patient populations and little is known about exposure of newborns to excipients. The aim of this review is to deepen the presence of potentially harmful excipients in drugs commonly used in neonates. From an analysis of articles and case reports present in the international literature emerges that several medicines administered to newborns contain potentially harmful excipients such as ethanol, propylene glycol and benzyl alcohol. Neonatologists should be aware of this problem and possibly prescribe substitutive treatments.