The present study examined reciprocal associations between children’s social competence and language and pre-literacy skills across the preschool year. Participants were 441 children (six-year-olds; 212 boys, 229 girls) and their teachers. Teachers rated children’s social competence in the autumn and again in the spring, using the Multisource Assessment of Social Competence Scale (MASCS), which produced sum scores for cooperating skills, empathy, impulsivity and disruptiveness. Children were tested by trained investigators on their pre-literacy skills in both the autumn and the spring, and, only in the spring, also on their receptive vocabulary. Parental education, each child’s age and time elapsed between the measurement points were used as control variables. The gender differences in the reciprocal associations were also investigated. The results showed that cooperating skills predicted a higher vocabulary. Associations between social competence and pre-literacy skills varied between boys and girls. For girls, empathy and cooperating skills predicted higher pre-literacy skills, whereas, for boys, pre-literacy skills predicted subsequent empathy. For boys, higher pre-literacy skills were related to lower disruptiveness and impulsivity, whereas, for girls, higher disruptiveness predicted lower pre-literacy skills. The findings highlight the reciprocal association between social-emotional and pre-literacy skills and emphasise the importance of promoting children’s overall development during the preschool year.