OBJECTIVES: We examined whether adults born preterm at very low birth weight (VLBW; <1500 g) differ from term-born adults in autism-spectrum traits, and whether among VLBW adults, growth in infancy is associated with these traits. METHODS: A total of 110 VLBW and 104 term-born adults of the Helsinki Study of Very Low Birth Weight Adults completed the Autism-Spectrum Quotient yielding total, social interaction, and attention to detail sum scores. Growth in weight, length, and head circumference from birth to term and from term to 1 year of corrected age was determined as standardized residuals reflecting growth conditional on previous history. RESULTS: VLBW adults scored higher than term-born controls on social interaction sum score, indicating higher autism-spectrum traits. In contrast, they scored lower on attention to detail sum score, indicating lower autism-spectrum traits. Within the VLBW group, faster growth in weight, length, and head circumference from birth to term was associated with lower total and social interaction sum scores. In this group, growth from term to 1 year was not associated with autism-spectrum traits. CONCLUSIONS: Among those born preterm at VLBW, the risk for higher levels of autism-spectrum traits, particularly related to social interaction, may persist into adulthood. Faster growth from birth to term may ameliorate these effects, suggesting that targeted interventions could aid long-term neurodevelopment.