Moral reasoning skills are crucial for appropriate and adaptive social functioning. Impairments in moral reasoning have been associated with aggressive and violent behaviours. Traditional measures of moral reasoning may provide limited insight into daily behavioural functioning as these measures are dependent on several higher order cognitive skills and, as such, may be limited in their utility with certain clinical populations. In Study 1, new measures of sociomoral reasoning and maturity, the So-Moral and So-Mature, were described. Further, the psychometric properties of the So-Moral and So-Mature were investigated in a sample of 50 adolescents aged 11 to 19 (mean age = 14.5, SD = 2.6 years, 25 male). Preliminary support was found for the validity and reliability of both tasks. In Study 2, the clinical applicability of the So-Moral and So-Mature were examined in a sample 25 adolescents with traumatic brain injury (TBI; mean age = 13.8, SD = 2.3 years, 15 male). Response trends suggested that adolescents with TBI generated less developmentally mature responses to sociomoral dilemmas and those with more severe injuries performed most poorly. The sociomoral reasoning tasks described promote participant's emotional involvement and investment as well as being appropriate for use with clinical populations.