This study examines the temperamental characteristics of children who were identified at age two as being slow in expressive language development, and those of peers with normal language history. When the children were in first grade (approximately age six), parents and clinicians rated subjects' temperamental characteristics, using a standardized temperament assessment instrument. Subjects with a history of slow expressive language development were rated significantly lower on Approach/Withdrawal--indicating shyness, aloofness, or reduced outgoingness--than peers with normal language history. Approach/Withdrawal scores were significantly correlated with average sentence length in spontaneous speech, and this measure also predicted Approach/Withdrawal scores in regression analyses. The clinical and theoretical implications of these findings for early language delay are discussed.