This cross-linguistic study investigated whether the native language has any influence on lexical composition among Italian (N = 125) and Finnish (N = 116) very preterm (born at <32 gestational weeks) children at 24 months (controls: 125 Italian and 146 Finnish full-term children). The investigation also covered the effect of maternal education (ME) on lexical composition. The Italian/Finnish MacArthur Communicative Development Inventory was used for gathering the data. Although the lexicons of the preterm children were smaller than those of the controls, the native language had no major effect on their lexical composition. The ME had a significant effect on preterm children's lexical composition, especially in the Finnish children. The findings indicate that lexical composition is not strongly affected by preterm birth. They also imply that lexical composition is a robust phenomenon that is connected to lexicon size and is not language-specific when analysed in broad terms, although some language-specific features were also detected.