The need for safe and effective use of medicines in children and WHO's initiative "Make Medicines Child Size" have boosted research and educational activities in the area of pediatric clinical drug research. This issue focuses on both general and specific aspects of neonatal and pediatric clinical pharmacology including ethics, pharmacogenomics, metabolomics, adverse drug reactions, pain medication, pulmonary hypertension and several other hot topics. The editors have been able to find outstanding authors for the different parts on neonatal and pediatric pharmacology.