Most immigrant parents face the challenge of passing on their heritage language to their children. Family predictors of Turkish heritage language vocabulary are examined for 119 preschoolers and 121 fourth graders in Germany. Path analyses link children's Turkish vocabulary to the family background (parents' education and generational status), the home literacy environment (HLE), and mothers' language use. The main findings are (a) the HLE predicts children's Turkish vocabulary, (b) mothers' use of Turkish with their children predicts children's Turkish vocabulary, and (c) family background is mainly connected to Turkish vocabulary by way of mothers' use of Turkish. The HLE and being exposed to Turkish are both important for children's heritage vocabulary. Thus, parents can use everyday resources to actively promote their children's Turkish language skills.