The present study investigated the longitudinal effects of early exposure to L2-English on L1-Turkish language competence, narrative skills and executive functioning. We asked whether early immersion-like exposure to L2, starting around 3 years of age, would have reflections on L1 competence, L1 narrative skills and gains in cognitive flexibility. Thirty 4-year-olds attending two types of preschools participated in the study: L1-preschools (N=12) with Turkish instruction and L2-preschools (N=18) where children were exposed only to English (6 hrs) throughout the day. Children were initially tested at time 1 (T1) at age 4 and at time 2 (T2), a year later when they were 5. At T1, results revealed that children attending L2-preschools displayed no differences in executive functions performance compared to children in L1-preschools. Likewise, there were no differences for L1 competence as well as L1 narrative skills. At T2, however, for L1 narrative skills, children attending L1-preschools displayed significantly higher performance compared to peers in L2-preschools. For executive functioning again there were no differences between the participants. The differences in narrative competence at T2 might indicate that children in L2-preschools lack sufficient input in story telling in L1 to support narrative competence. For future consideration how literacy acquisition would interact with the effects of L2 exposure should also be investigated.