In contrast to adults, 50% or more of medicines used in children have never been actually studied in the paediatric population in the European Union community (EU). Under the impression that compliance with good clinical practice (GCP) requirements will lead to an improved quality of clinical trials, the ratification of the EU Directive 2001/20/EG now imposes the same GCP regulations demanded for commercial clinical trials on non-commercial trials or so-called investigator-initiated trials (IITs). Although it is desirable that all clinical trials comply with ICH-GCP, ensuring that an IIT conforms creates a significant burden for the principal investigator, turning an IIT into a substantial logistic, administrative and financial enterprise. This can only be achieved with a multidisciplinary approach, including physicians, statisticians, data managers, administrators and others. In particular, 'treatment optimization studies'--the most important clinical trials in paediatric oncology--are affected by this new law, potentially resulting in significant delays in the implementation of new and innovative treatment strategies in the paediatric population. This significant drawback was not foreseen but is now recognized and lead to measures to improve the situation for both non-commercial and paediatric clinical trials. Draft guidance on 'specific modalities for non-commercial trials', posted for comment last October, attempts to redress some of the research-crippling problems caused by the initial legislation; however, major problems remain. The EU regulation (EC) no. 1901/2006 'on medicinal products for paediatric use' was enacted in January 2007. This new regulation is a promising step in the right direction, as it will facilitate the development and accessibility of medicinal products specifically for use in children. To adapt to and benefit from this new situation and encourage IIT, a coordinated approach of high expertise is necessary to support and guide the novice in the field of IIT to successfully launch, conduct and complete clinical trials especially in children.