This study focuses on the early temperamental (TTQ = toddler temperament questionnaire), behavioral (IBR = infant behavior record), and cognitive precursors of impaired language functioning in preschool-age pre-terms infants. The study group consisted of 63 pre-term infants with a mean birth weight of 1246 +/- 437 g born in 1989-1991 in the University Central Hospital of Helsinki. Children with major disabilities (CP or mental retardation) were excluded. At the age of 4 years, 22% showed impaired language function. Logistic regression analysis showed that the Bayley MDI score was the best predictor in identifying an increased risk for language impairment. Behavioral characteristics were more strongly associated with subsequent language impairment than temperament.