A number of medications do not have a licence, or label, for use in the paediatric age group nor for the specific indication for which they are being used in children. Over recent years, mycophenolate mofetil has increasingly been used off-label (i.e. off-licence) in adults for a number of indications, including autoimmune conditions; progressively, this wider use has been extended to children. This review summarizes current use of mycophenolate mofetil (MMF) in children, looking at how MMF works, the pharmacokinetics, the clinical conditions for which it is used, the advantages it has when compared with other immunosuppressants and the unresolved issues remaining with use in children. The review aims to focus on off-label use in children so as to identify areas that require further research and investigation. The overall commercial value of MMF is limited because it has now come off patent in adults. Given the increasing knowledge of the pharmacodynamics, pharmacokinetics and pharmacogenomics demonstrating the clinical benefits of MMF, new, formal, investigator-led studies, including trials focusing on the use of MMF in children, would be of immense value.