The quality of early student-teacher relationships (STRs) has been shown to predict children's school adjustment, and children with autism spectrum disorder (ASD) are at risk for poor quality STRs. The present study examined 162 children with ASD (ages 4-7) and their teachers to evaluate student, teacher, and classroom characteristics that predicted concurrent and prospective STR quality across one school year. Child oppositional behavior, autism severity and teacher degree predicted changes in student-teacher conflict over a 1-year period, while child social skills and IQ positively predicted change in student-teacher closeness. Teacher preparedness, trainings in ASD, and classroom setting were unrelated to STR quality. Implications for intervention are discussed.