Given their lower socioeconomic background and achievement, immigrants and their descendants have been shown to make more ambitious decisions regarding educational transitions. While previous research has extensively analysed transitions within and after compulsory education, research on late transitions is scarce. This study focuses on the secondary effect of ethnic origin in the transition after upper secondary education in Germany, where school leavers decide between vocational education and training and higher education. Based on longitudinal data from the National Educational Panel Study, we first analyse differences by ethnic origin (Turkey, former Soviet Union, Poland, other countries) and immigrant generation (first, second, third generation) net of socioeconomic background and achievement. Compared to those of the ethnic majority, we find increased probabilities of enrolment in higher education for most ethnic groups of the first and second immigrant generation, net of differences in socioeconomic background and achievement. Second, we test four explanatory approaches for secondary ethnic effects (immigrant optimism, relative status maintenance, anticipated discrimination, and information deficits). By employing decomposition analyses for nonlinear regression models, we find that, taken together, the four explanations account for up to half of the ethnic differences in educational choice after upper secondary education. Specifically, increased levels of immigrant optimism and information deficits regarding vocational education explain a substantial share of the ethnic differences among all origin groups. For Turkish immigrants, the motive to maintain relative status in the origin country also contributes to increased enrolment rates in higher education.