The present study utilized a short-term longitudinal research design to model the relationship between shyness-anxiousness and receptive language skills. Hypotheses regarding the direction of the causal relationship, mediation, and moderation were evaluated. Subjects included 340 Head Start attendees from primarily English- and Spanish-speaking homes. Results suggest that a unidirectional relationship between shyness-anxiousness and receptive language skills emerges in preschool. Shyness-anxiousness impacted receptive language skills and this relationship was mediated by communication competence. Neither gender nor native language moderated the indirect relationship from shyness-anxiousness to receptive language through communication competence. These results are discussed with respect to elucidating the nature of the bidirectional relationship between shyness-anxiousness and language skills and identifying intervention targets to improve language outcomes for shy-anxious preschoolers. (Contains 2 figures and 2 tables.)