The purpose of this exploratory study was to examine child and environmental factors known to be associated to language development and how they relate to results in expressive vocabulary, expressive language, and receptive language in language-delayed toddlers. The cross-sectional data on 96 French-speaking children aged 18–36 months were gathered at the point of entry into a longitudinal study of 2-year-old children displaying language delay. Measures of language, child development, and child and environmental factors were administered. When several factors individually associated with language development were considered concurrently, cognitive development was consistently associated with the outcomes. Other child factors, such as male gender and age, were also retained in the regression model explaining expressive vocabulary, whereas only age was added in the model explaining expressive language. Two environmental factors were involved in receptive language; that is, parental education and parental stress accounted for 8% of the variance. Factors linked to development varied across language modalities such that parental education and parental stress were related to comprehension but not to production. The findings suggest a strong biological trajectory for expressive language development and vocabulary production, which are not affected by environmental factors.