OBJECTIVE: Language problems are thought to occur more frequently in very preterm children compared with healthy term born children. The primary aim of this study was to examine the contributions of biological and environmental risk factors to language outcomes in very preterm children at 5 years of age. METHODS: A cohort of 227 very preterm infants (birth weight <1250 g or gestational age <30 weeks) were recruited at birth and followed up at 2 and 5 years of age (corrected for prematurity) in a prospective, longitudinal study in Melbourne, Australia. Outcomes at 5 years of age were the Expressive and Receptive Language Scales from the Kaufman Survey of Early Academic and Language Skills. A range of hypothesized biological and environmental factors identified from past research were examined as predictors of language outcomes at 5 years of age using linear regression models. RESULTS: Lower maternal education and poorer communication skills in the child at 2 years of age were predictive of poorer expressive and poorer receptive language outcomes at 5 years of age. Lower expressive language scores were also associated with the presence of moderate-severe white matter abnormalities on neonatal magnetic resonance imaging. CONCLUSIONS: Results support the role of both biological and environmental factors in the evolution of language difficulties and highlight the need to consider these factors in the follow-up of preterm infants.