There is considerable debate about the sociocognitive features of autism spectrum conditions (ASC), and a tool for profiling the sociocognitive profiles of children and adolescents with ASC is needed. The aim of this research was to evaluate the psychometric properties of a new questionnaire—The Australian Scale for Autism Spectrum Conditions (ASASC). Three hundred twenty-two parents of children on the ASC spectrum, including autistic disorder (n = 76), Asperger's disorder (n = 188), and pervasive developmental disorder not otherwise specified (n = 21), and a clinical group of children with subclinical ASC features and no ASC diagnosis (n = 37). Measures include an initial scale measuring eight potential dimensions of ASC, a related screening tool for autism, and two previously validated social skills questionnaires. The questionnaires were administered online. The ASASC was factor-analysed, internal and test–retest reliabilities (for a randomly selected 84 parents) were calculated, and preliminary tests of convergent and divergent validity were conducted. The resulting measure (44 items) contained five coherent and reliable dimensions: understand and express emotion, fact orientation, sensory sensitivity, social communication, and rigidity. The questionnaire had good test–retest reliability and convergent/divergent validity. The ASASC enables profiles of ASC symptomatology that should be useful in adjusting interventions to individual needs.