Using matched employer-employee data on more than 62,000 master’s graduates, this paper examines how gender differences in wage returns to fields of study vary by migration background and how educational specialisation contributes to the gender wage gap. We estimate wage regressions and apply a decomposition approach to separate sorting across fields from differences in pay within fields. Returns vary widely, with law, economics and management, and science yielding the highest returns, and women earning less than men within all fields, especially in high-paying ones. First-generation immigrants from developing countries obtain the lowest returns regardless of field of study, while second-generation immigrants approach but do not fully match natives. Fields of study explain a substantial share of gender wage inequality among natives and second-generation immigrants, whereas among first-generation immigrants broader wage disadvantages dominate. Results further vary with the number of parents originating from developing countries and with age at arrival.