The aim of this study was to analyse the existence of differences in lexical development as a function of day care attendance and maternal education. Data were collected using the MacArthur-Bates Communicative Development Inventory: Words and Sentences. The reports of 2084 toddlers were analysed. The results for toddlers older than 24 months indicated that those from mothers with higher educational levels produced a higher number of words in all lexical categories than those from mothers with lower educational levels. When considering younger toddlers, a significant effect of maternal education was only found on the number of common nouns produced. Nevertheless, the size of these effects was small. Quantity of day care attendance had no effect on the number of words produced. No interaction effects between maternal education and day care attendance were found. These findings indicate that maternal education may be differently associated with the production of words from different lexical categories.