The present study examined lexical richness in maternal input to Turkish preschool children in the Netherlands and the relationship with their vocabulary. Fifteen Turkish mother-child dyads were videotaped at the age of 3 and 4 in three settings: book reading, picture description and block building. Children's vocabulary in Turkish was measured at the age of 3 and 4 and in Dutch at the age of 5;10. The lexical richness of the input was analysed both quantitatively (tokens) and qualitatively on diversity, density, and sophistication. The results indicate that lexical richness varied largely among mothers, which could partially be attributed to their SES levels and literacy practices. Furthermore, lexical richness differed between the settings, with the highest richness in the book setting. More importantly, lexical richness in maternal input related to the vocabulary of children in L1 (Turkish) and in the longer run also to L2 (Dutch). Quality of the input (diversity, density and sophistication) turned out to be more influential than quantity.