Children with an immigrant background are often regarded as a risk group for poor educational outcomes due to their on average lower levels of German language skills. However, the heterogeneity within this group is often neglected when only averages are considered. We address this heterogeneity by analyzing patterns of German vocabulary development in early childhood among children with and without immigrant background with an explorative approach. Using the data from the newborn cohort of the National Educational Panel Study (NEPS), we examine children’s German vocabulary trajectories from age three to nine by applying Growth Mixture Modeling. Our results show that a large share of children with an immigrant background exhibit an average or even above-average vocabulary trajectory. However, almost a fifth can be considered as having a “risk profile” since they show very below-average vocabulary levels at all measurement points. Such a risk profile also exists in the sample of non-immigrant children, but the share is smaller. The number of books in the family, the family language and children’s early cognitive skills are the strongest predictors for being in this risk profile.