It is a well-established finding in the literature that immigrants make ambitious educational choices. Once controlling for prior achievement and socioeconomic status, children of immigrants are more likely than natives to switch to the more demanding educational tracks. However, less is known about whether immigrants can actually benefit from these optimistic choices in terms of educational attainment or whether they have a higher risk of dropping out from the more demanding tracks. By focusing on a representative sample of adolescents with and without immigrant background in Germany, this contribution investigates how enrolment and completion rates change over time—from the end of lower secondary education until the end of upper secondary education—and how this affects ethnic inequalities in educational outcomes. When comparing academic completion rates and academic enrolment rates in grade 9, we observe long-term improvements within the immigrant group as a result of immigrants’ ambitious choices. When comparing both outcomes between natives and immigrants, however, ethnic differences in academic completion rates remain comparable to the disparities in enrolment rates as observed in grade 9.