A longitudinal field survey tested the reciprocal effects of acculturation preferences and prejudice among ethnic minorities and majorities. Data were collected at two points in time from 512 members of ethnic minorities and 1143 majority members in Germany, Belgium and England. Path analyses yielded not only the lagged effects of prejudice on acculturation preferences but also the reverse for both majority and minority members. The mutual longitudinal effects between prejudice and desire for culture maintenance were negative, and the mutual effects between prejudice and desire for culture adoption were positive for majority members. The reverse was the case for minority participants. Moreover, the two acculturation dimensions interacted in their effect on prejudice for majority participants but not for minority participants. The effect of desire for culture adoption on prejudice was moderated by perceived intergroup similarity. Theoretical and practical implications of the findings are discussed.