Children with autism spectrum disorder from low-income, minority families or those with limited English proficiency are diagnosed at a later age, or not at all, compared with their more advantaged peers. The Developmental Check-In is a new tool that could potentially be used to screen for autism that uses pictures to illustrate target behaviors. It was developed to enhance early identification of autism spectrum disorder in low literacy groups. The Developmental Check-In was tested in a sample of 376 children between the ages of 24 and 60 months, from underserved communities. It showed good ability to discriminate autism spectrum disorder from non-autism spectrum disorder (area-under-the-curve = 0.75) across the full age range represented in the sample. Twenty-six of the 28 Developmental Check-In items predicted the presence of autism spectrum disorder. Findings suggest that this pictorial tool may reduce linguistic and health literacy demands when screening for autism among vulnerable populations.