Aims. To determine the effect of introducing an action plan to children with mild to moderate asthma, who have never used a plan before. Methods Children were recruited from general practitioner records with a diagnosis of asthma, and who agreed to participate, having identified that they had not used an action plan before and that they had mild or moderate asthma based upon symptoms, acute episodes and the need for preventative medication. The families were given a plan, and its use was explained to them by their general practitioner. A symptom diary was kept, and, where appropriate, peak flow measurements were recorded. A number of outcomes were measured to determine changes that could be attributed to the introduction of the plan. Results. Following the introduction of the plan, the percentage of nights woken for asthma fell from 18.2% to 12.2% (p<0.001) and the number of days out of action fell from 6.4 to 4.1 (p<0.001) The requirement for acute medical treatment also fell during the intervention period with general practitioner visits falling from 129 to 42 (p<0.001). Most participants commented favourably about the usefulness of the plan in giving them a better idea of the state of their asthma at any time, and in knowing what to do about it. Conclusions. The children's action plan, when introduced into a group of asthmatic children was effective and acceptable in the self management of asthma.