Purpose: This paper examines the developmental continuity from prelinguistic communication to kindergarten age in language and working memory capacity. Method: Following our work outlining six groups of children with different trajectories of Early Communication Development (ECD, Määttä et al., 2012), we examined their later development by psychometric assessment. Ninety-one children first assessed at age 12 to 21 months completed a battery of language and working memory tests at age 5;3 (years; months). Results: Two of the ECD groups previously identified as being at risk for language difficulties continued to show weaker performance at follow-up. The majority (79 %) of the children with compromised language skills at follow-up were identified on the basis of the ECD groups, but the number of false positives was high. The two at-risk groups also differed significantly from the typically developing groups in the measures tapping working memory capacity. Conclusions: In line with the dimensional view of language impairment, the accumulation of early delays predicted the amount of later difficulties; however, at the individual level the prediction had rather low specificity. The results imply a strong link between language and working memory and call for further studies examining the early developmental interaction between language and memory.