Interventions for preschool children with autism typically require professionals and parents to identify which social and language skills the individual child shows deficits in. Many assessment tools aimed at identifying such deficits exist, but they often require extensive training to use. The present study investigated the potential usefulness for said assessment purposes of the Norwegian assessment tool, TRAS – “Tidig Registrering Av Språkutveckling” (i.e. Nordic acronym for assessment of early language development), which can be used by preschool teachers without any specific training. Participants were 54 children with ASD, aged 2–5 years, enrolled in a behavioral intervention program. Participants were scored using TRAS at three time points during treatment to investigate TRAS’ sensitivity for detecting change. Only participants who had TRAS scores registered at all three time points were used for this analysis (n = 27). At intake, children were also scored using the Vineland Adaptive Behavior Scales, the results of which was then compared to TRAS scores. Results showed that TRAS scores increased significantly across time points, indicating that the tool is sensitive to treatment effects. TRAS scores also correlated significantly with Vineland communication subscale (n = 50), indicating that the measure can be used to measure language abilities in children with ASD. We conclude that TRAS is a potential alternative to more comprehensive language assessment tools for children with ASD.