We present findings on psychological changes among students following a semester abroad by exploring how ethnic identity (commitment and exploration) changes in association with shifts in acculturation orientations, perceived cultural distance, and initial language proficiencies. We used longitudinal multilevel modelling with two-time points separated 3 to 4 months among Czech students abroad (N=140) and Czech controls (N=133) at home. International students decreased in identity commitment (a sense of belonging to their ethnic group) and did not change in identity exploration (examining and reflecting upon their ethnic belonging). However, those international students that grew in home acculturation orientation (adherence to their culture of origin) over the semester did increase in identity commitment. Also, when international students grew in home as well as host orientation (involvement with the host culture), they also increased in identity exploration. Initial host language proficiency was a predictor of growth in identity exploration (but not commitment). English proficiency, perceived cultural distance (subjectively viewed cultural differences between homeland and the host country), and expatriate orientation (involvement with the expatriate culture) had no effect. The control group increased in both identity commitment and exploration. Our findings show that ethnic identity can change after social contacts and communication with members of different cultures.