Empirical evidence shows that immigrants adapt best in relation to their ability to negotiate between the cultural entities they confront. Factors such as cultural knowledge, length of stay in the new culture, and linguistic competence strongly influence this process. Length of stay and linguistic competence may be essential for cultural knowledge acquisition that, in turn, may be enhanced by mass media consumption. A questionnaire is completed by 576 immigrants (196 Romanians, 179 North Africans, and 201 Latino Americans) investigating time spent in Italy, proficiency in the Italian language, familiarity with Italian and homeland mass media, and acculturation. The authors hypothesize that language plays a central role in the acculturation process and assume that length of stay influences acculturation mostly through linguistic competence and mass media knowledge. A structural equation model is tested to verify the hypothesis. The model results are acceptable, invariant across genders, and partially invariant across ethno-cultural groups.