Medicines' management or pharmaceutical care in paediatric patients is particularly demanding, mainly because the majority of available drugs have been developed for use in adults. As a result, in children, drugs are often unlicensed or used off-label, suitable formulations or appropriate strengths are lacking, and drugs have to be extemporaneously prepared, liquids and injections diluted, and tablets split. These factors increase the likelihood of medication errors and may lead to a reduction in drug effect. Age-specific changes in pharmacokinetics and pharmacodynamics further complicate drug therapy in children. All these challenges provide unique opportunities for pharmacists to improve the quality of care for paediatric patients. We conducted a systematic literature review examining whether the interventions of hospital pharmacists improve drug therapy in children. Several medical and pharmaceutical databases were searched systematically to identify articles investigating hospital pharmacists' interventions that were intended to improve drug therapy in children. Inclusion criteria were English language, primary research papers and studies in which clinical pharmacists contributed directly to patient care. Exclusion criteria were reviews, editorials, questionnaire studies, modelling studies, letters and studies only available in abstract form. This systematic search identified 18 articles documenting the role of a clinical hospital pharmacist in paediatric care. These articles were divided into the following groups based on study type: (i) studies documenting interventions made by pharmacists and their role in inpatients; (ii) articles presenting the outcomes of a satellite pharmacy; and (iii) articles examining pharmacist involvement in paediatric outpatient clinics. No randomised study comparing pharmacist interventions with standard care was found. In conclusion, although it was difficult to compare the various studies identified because of the different settings, design, duration, size, methodology and definition, all these studies highlighted the importance of hospital pharmacists to medicines' management in paediatric patients. On the basis of this review, we can conclude that pharmacist reviewing of medication charts is very important in identifying medication errors; hence, it is likely to be the most effective method of improving drug therapy in children.