Human biomonitoring is a promising tool for assessing environmental exposure and its potential relation with biomarkers, diseases and/or disorders in humans including children. Research with children is essential; however, if the research questions can be resolved by recruitment of adults it is not justified to include children. In general, considerations of using the less-invasive techniques and cost-efficiency have to be taken into account. All stakeholders, especially the participants should be well informed on the aim, procedures, benefits and risks, right to withdraw before the kick-off and the recruitments. In the initial phase of planning a biomonitoring study consideration of communication of results including risk and means of risk prevention should be made. Ethical considerations regarding the study protocol should take into account (a) justification of biological sampling related to the expected outcome(s), (b) causing no harm to the child, (c) appropriate and comprehensive communication to the participating child as well as the parents and tutors, (d) informed assent or consent including the right to withdraw (e) communication of results to research participants and (f) access to own data respecting data protection including the right to know or not to know. Data protection is important because stakeholders may also ask for insight at various steps during human biomonitoring activities including children. Finally it is generally recommended that aim, methods, and results from biomonitoring studies should be communicated and study persons notified for further use of data and samples.