One-to-one instruction is a critical component of evidence-based instruction for students with autism spectrum disorder, but is not used as often as recommended. Student characteristics may affect teachers' decisions to select a treatment and/or implement it. This study examined the associations between students' clinical and demographic characteristics and teachers' reported use of discrete trial training (DTT) and pivotal response training (PRT). Children's higher sensory symptoms, lower social approach, lower verbal skills and higher self-regulation difficulties were associated with more frequent 1:1 DTT and PRT. Results suggest that teachers give more frequent 1:1 instruction to children with more observable impairments, do not match children to type of 1:1 intervention, and may inadvertently neglect other students for whom individualized intervention may still be beneficial.