Recently, there has been a surge of interest and research in social functioning throughout childhood and adolescence, and how social development is affected by acquired brain injury (ABI). Despite ongoing research and theoretical advances, there remains a lack of specific, relevant and robust measurement tools that draw upon current clinical and social neuroscience knowledge, and which are developmental in nature, to assess social competence within the nonclinical and the ABI population. The aim of the current project was to develop a questionnaire to measure social competence and the quality of relationships of children and adolescents between the ages of 5 and 18 years. This questionnaire, the Developmental Assessment of Social Competence (DASC), also aimed to be sensitive to the specific social problems often associated with children who have suffered ABI. The current article outlines the process and challenges faced in developing such a measure up to the initial pilot stage. Participants included a pilot group of 40 parents who completed the pilot questionnaire, as well as an established questionnaire that assesses social functioning. Parents rated their own children who were aged between 6 and 14 years, and who were within the nonclinical population. Preliminary analyses found that the children generally scored highly on the DASC, and that a higher score on most scales of the DASC tended to be associated with a higher score on an established questionnaire measuring social skills. These data are promising, and provide important information for the following stages of development and evaluation of this new questionnaire.